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Conflicts between humans and land use in the process of using water and conflicts between humans and water resources in the process of using land have led to an imbalance between natural ecosystems and socio-economic systems. It is difficult to understand the impact of the processes of water production and consumption on land patches and their ecological effects. A grid-type, basin-distributed hydrological model was established in this study, which was based on land-use units and coupled with groundwater modules to simulate the water production and consumption processes in different units. By combining land use and net primary productivity, the runoff coefficient and the water use efficiency (NPP/ET) of different land units were used as indicators to characterize the interaction between water and land resources. The results showed that the average runoff coefficients of cultivated land, forest land and grassland were 0.7, 0.5 and 0.9, respectively. Moreover, the average runoff coefficients of hills, plains and basins were 0.7, 0.7 and 0.8, respectively. The NPP produced by the average unit, evapotranspiration, in cultivated land, forest land and grassland was 7 (gC/(m2•a))/mm, 0.7 (gC/(m2•a))/mm and 0.2 (gC/(m2•a))/mm, respectively. These results provide quantitative scientific and technological support in favor of the comprehensive ecological management of river basins.

The mismatch of water and land resources leads to various water problem and degradation of ecological function in the basin. The existing water resources allocation and land resource allocation have different objects, basic units, allocation goals and methods, and it is difficult to achieve joint allocation on a unified platform. This paper takes the water and land resources system as the research object. The optimal allocation model of water and land resources was constructed, with the multiple objectives, from aspects of water quantity, water quality, water efficiency, ecological function and the matching degree of water and land resources. The constructed model is used to allocate water and land resources in Sihe River basin, and the results of water and land resources allocation of each configuration unit under different water supply conditions are obtained. This provides technical support for the synthetically delicacy management of water and land resources based on the land unit in the river basin.

Aims: To analyze the consistency between HPV-neutralizing antibodies and specific total IgG antibodies in unvaccinated females. Materials & methods: Serum samples from 978 unvaccinated Chinese females aged 9–26 years were measured for antibodies against HPV-16 and HPV-18 using simultaneous pseudovirus-based neutralization assay and ELISA. Results: There was a moderate level of consistency between HPV-neutralizing antibodies and specific IgG in females aged 18–26 years (Cohen's κ coefficient for HPV-16 and HPV-18: 0.52 and 0.38) and poor consistency in those aged 9–17 years (Cohen's κ coefficient

The rainfall in loess hilly and gully area is concentrated, and mostly comes in the form of rainstorms. The runoff on the slope caused by rainstorms is the main cause of serious soil and water loss in the loess hilly area, and the grassland vegetation has a good inhibitory effect on the runoff on the slope. Therefore, it is of great significance to reveal the role of grassland vegetation in the process of runoff generation, and the mechanisms for controlling soil erosion in this area. In this study, typical grassland slopes in hilly and gully regions of the loess plateau were taken as research objects. Through artificial rainfall in the field, the response rules of the slope rainfall-runoff process to different grass coverage were explored. The results show that: (1) With the increase in rainfall intensity, the inhibitory effect of grassland vegetation on slope runoff decreased, which was mainly reflected in the gradual decrease in runoff rate and runoff coefficient, and the time required to reach stability gradually shortened. (2) Under 60 mm/h rainfall intensity, the sensitivity of runoff coefficient to 31.5% of grass cover change is the lowest, and the cost performance of grass cover with 55% coverage is the highest. (3) Grass coverage inhibited slope runoff by changing the hydraulic characteristics of the slope, but this effect was only obvious in low rainfall intensity and early rainfall. Rainfall in the loess hilly area is characterized by intense rain. The regulating effect of grass cover on slope runoff is not particularly significant under high intensity rainfall. If only considering the regulation of grassland vegetation on slopes, more than 60% grassland coverage is more efficient in inhibiting slope runoff under medium and low intensity rainfall.

Climate changes and underlying surface of the watershed have affected the evolution of streamflow to a different degree. It is of great significance to quantitatively evaluate main drivers of streamflow change for development, utilization, and planning management of water resources. In this study, the Huangshui River basin, a typical basin of the Qinghai-Tibetan Plateau, China, was chosen as the research area. Huangshui is the largest first-class tributary in the upstream of the Yellow River. Based on the Budyko hypothesis, streamflow and meteorological datasets from 1958 to 2017 were used to quantitatively assess the relative contributions of changes in climate and watershed characteristics to streamflow change in research area. The results show that the streamflow of Huangshui River basin shows an insignificant decreasing trend; the sensitivity coefficients of streamflow to precipitation, potential evapotranspiration, and watershed characteristic parameter are 0.5502, −0.1055, and −183.2007, respectively. That is, 1 unit increase in precipitation would induce an increase of 0.5502 units in streamflow, and 1 unit increase in potential evapotranspiration would induce a decrease of 0.1055 units in streamflow, and an increase of 1 unit in the watershed characteristic coefficient would induce a decrease of 183.2007 units in streamflow. The streamflow decreased by 20.48 mm (13.59%) during the change period (1994–2017) compared with that during the reference period (1958–1993), which can be attributed to watershed characteristic changes (accounting for 73.64%) and climate change (accounting for 24.48%). Watershed characteristic changes exert a dominant influence upon the reduction of streamflow in the Huangshui River basin.

The dense medium modulates the molecular structure and bioreactions in living cells via both noncovalent interactions and macromolecular crowding and confinement effects. However, the interplay between the volume effect and noncovalent interactions remains unclear. In this work, we studied in detail on how electrostatic interactions influence the crowding and confinement effect by comparing the formation and elongation of DNA nanotubes in branched dextran and charged hyaluronic acid (HA) solution of a broad concentration range, with and without 150 mM NaCl. In all the studied cases, three concentration regimes are identified: a crowding regime, a double-effect regime, and a confinement regime. In the crowding and double-effect regimes, the addition of 150 mM NaCl enhances the assembly of DNA tiles by screening the electrostatic repulsion, and a higher dextran solution is required to confine the DNA assembly into nanotubes. However, the screening effect on the HA network is more than that on the DNA assembly, so DNA tubes formed in HA solution at much lower concentrations. In the confinement regime, the electrostatic interaction exhibits a negligible effect on the DNA assembly in both dextran medium and HA medium. Our study demonstrates that the volume effect and noncovalent interactions are system specific and concentration dependent. Their interplay governs the living processes in crowded cells.

Among numerous research studies focusing on macromolecular crowding and confinement, few are concerned with the medium at a broad range of concentrations, let alone the interplay between the crowdi...

Many studies have qualitatively analyzed the response of hydrological characteristics to climate change in Haihe river basin, but quantitative research has been rare, which is essential for water resource management. To evaluate and quantitatively analyze the relationship between catchment runoff capacity and environmental factors, principal component analysis, step regression analysis, and sensitivity analysis were conducted. The results show that the runoff capacity of Haihe river basin was mainly controlled by vegetation types and soil texture; catchments with lower runoff capacity were mainly distributed in the upstream/northwest regions. In the catchments with middle runoff capacity, a 10% increase in precipitation (PRE), potential evapotranspiration (PE), and plant-available water coefficient (PAWC) would result in a 23.6% increase, 12.9% decrease, and 5.1% decrease in annual runoff, respectively, whereas in low runoff capacity catchments, a 10% increase in slope and leaf area index (LAI) would result in a 17.8% increase and 10.5% decrease in annual runoff, and in high runoff capacity catchments, a 10% increase in normalized differential vegetation index (NDVI) would result in a 12.6% increase in annual runoff. Soil conditions and vegetation configuration improvement in the upstream of Haihe river basin may contribute to the improvement of available water resources.

The slope runoff caused by rainstorm is the main cause of serious soil and water loss in the loess hilly area, the grassland vegetation has a good inhibitory effect on the slope runoff, it is of great significance to reveal the role of grassland vegetation in the process of runoff generation and control mechanism for controlling soil erosion in this area. In this study, typical grassland slopes in hilly and gully regions of the loess plateau were taken as research objects. Through artificial rainfall in the field, the response rules of slope rainfall-runoff process to different grass coverage were explored. The results show that: (1) The time for the slope flow to stabilize is prolonged with the increase of vegetation coverage, and shortened with the increase of rainfall intensity; (2) At 60 mm·h −1 rainfall intensity, the threshold of grassland vegetation coverage is 75.38%; at 90 mm·h −1 rainfall intensity, the threshold of grassland vegetation coverage is 90.54%; at 120 mm·h −1 rainfall intensity, the impact of grassland vegetation coverage on runoff is not significant; (3) the Reynolds number and Froude number of slope flow are 40.07‒695.22 and 0.33‒1.56 respectively, the drag coefficient is 1.42‒43.53. Under conditions of heavy rainfall, the ability of grassland to regulate slope runoff is limited. If only turf protection is considered, about 90% of grassland coverage can effectively cope with soil erosion caused by climatic conditions in loess hilly and gully regions. Therefore, in loess hilly areas where heavy rains frequently occur, grassland's protective effect on soil erosion is obviously insufficient, and investment in vegetation measures for trees and shrubs should be strengthened.

In the past 60 years, climate changes and underlying surface of the watershed have affected the structure and characteristics of water resources to a different degree It is of great significance to investigate main drivers of streamflow change for development, utilization and planning management of water resources in river basins. In this study, the Huangshui Basin, a typical tributary of the upper Yellow River, is used as the research area. Based on the Budyko hypothesis, streamflow and meteorological data from 1958-2017 are used to quantitatively assess the relative contributions of changes in climate and watershed characteristic to streamflow change in research area. The results show that: the streamflow of Huangshui Basin shows an insignificant decreasing trend; the sensitivity coefficients of streamflow to precipitation, potential evapotranspiration and watershed characteristic parameter are 0.5502, -0.1055, and 183.2007, respectively. That is, an increase in precipitation by 1 unit will induce an increase of 0.5502 units in streamflow, and an increase in potential evapotranspiration by 1 unit will induce a decrease of 0.1055 units in streamflow, and an increase in the watershed characteristic parameter by 1 unit will induce a decrease of 183.2007 units in streamflow. Compared with the reference period (1958-1993), the streamflow decreased by 20.48mm (13.59%) during the change period (1994-2017), which can be attribution to watershed characteristic changes (accounting for 73.64%) and climate change (accounting for 24.48%). Watershed characteristic changes exert a dominant influence upon the reduction of streamflow in the Huangshui Basin.

The membraneless organelles (MLOs) and coacervates of oppositely charged polyelectrolytes are both formed by liquid-liquid phase separation. To reveal how the crowded cell interior regulates the MLOs, we chose the coacervates formed by peptide S5 and single-stranded oligonucleotide (ss-oligo) at 1:1 charge ratio and investigated the phase separation processes in polyacrylamide (PAM) and poly(ethylene oxide) (PEO) media at varying concentrations. Results show that the droplet formation unit is the neutral primary complex, instead of individual S5 or ss-oligo. Therefore, the coacervation process can be described by the classic theory of nucleation and growth. The dynamic scaling relationships show that S5/ss-oligo coacervation undergoes in sequence the heterogeneous nucleation, diffusion-limited growth, and Brownian motion coalescence with time. The inert crowders generate multiple effects, including accelerating the growth of droplets, weakening the electrostatic attraction, and slowing down or even trapping the droplets in the crowder network. The overall effect is that both the size and size distribution of the droplets decrease with increasing crowder concentration, and the effect of PEO is stronger than that of PAM. Our study provides a further step toward a deeper understanding of the kinetics of MLOs in crowded living cells.

China has carried out many ecological restoration projects in the past. At present, there are large spatial differences in the hydrological effects of forest ecosystems in different regions of the country under heterogeneous conditions, which is not conducive to the macro guidance of ecological restoration projects. Canopy interception is an important link in the water cycle of the ecosystem. This paper attempts to use this index as a bridge to connect the research literature of existing ecological sites, so as to evaluate the differences in water resources distribution in different regions and vegetation ecosystems and analyze the main reasons for the differences. We combined canopy interception rate (I0) and canopy water storage ability (I) to interpret canopy interception, and collected site related geographic, meteorological and ecosystem structure information simultaneously in the literature to build up an original dataset. Analysis on the database showed that the comprehensive interception capacity of vegetation in the south was generally higher than that in the north, which was dominated by shrubs, and that the tree species had interception advantages. Mixed forest showed the best comprehensive interception capacity, while pure tree forest had better interception potential than shrubbery due to its biomass advantage. The actual interception capacity of shrubbery was better than pure tree forest due to the advantages of stand density and the dry climate. Results from the evaluation of canopy interception ability using different indexes were not consistent, meaning that evaluating canopy interception with multiple indexes may be more objective. The study also highlights that the current structural characteristics of shrubby forests in northern China may be counterproductive to mitigating drought, reducing the structural density of a given stand will increase the opportunity for precipitation to reach the surface, thereby increasing the amount of water available to ecosystems in arid areas. Maintaining the healthy growth of mixed forests is still the right choice for humid areas in the south.

SIRT6, a member of the SIRT deacetylase family, is responsible for deacetylation of histone H3 Ne-acetyl-lysines 9 (H3K9ac) and 56 (H3K56ac). As a tumor suppressor, SIRT6 has frequently been found to have low expression in various cancers. Here, we report the identification of MDL-800, a selective SIRT6 activator. MDL-800 increased the deacetylase activity of SIRT6 by up to 22-fold via binding to an allosteric site; this interaction led to a global decrease in H3K9ac and H3K56ac levels in human hepatocellular carcinoma (HCC) cells. Consequently, MDL-800 inhibited the proliferation of HCC cells via SIRT6-driven cell-cycle arrest and was effective in a tumor xenograft model. Together, these data demonstrate that pharmacological activation of SIRT6 is a potential therapeutic approach for the treatment of HCC. MDL-800 is a first-in-class small-molecule cellular SIRT6 activator that can be used to physiologically and pathologically investigate the roles of SIRT6 deacetylation.

Currently there is no successful platform technology for the sustained release of protein drugs. It seems inevitable to specifically develop new materials for such purpose, and hence the understanding of protein–material interactions is highly desirable. In this study, we synthesized cholesterol-grafted polyglutamate (PGA-g-Chol) as a hydrophobically-modified polypeptide, and thoroughly characterized its interaction with a model protein (human serum albumin) in the aqueous solution by using circular dichroism, fluorescence methods, and light scattering. With the protein concentration fixed at 5 μmol/L, adding PGA-g-Chol polymers into the solution resulted in continuous blue shift of the protein fluorescence (from 339 to 332 nm), until the polymer molar concentration reached the same value as the protein. In contrast, the un-modified polyglutamate polymers apparently neither affected the protein microenvironment nor formed aggregates. Based on the experimental data, we proposed a physical picture for such protein–polymer systems, where the polymer first bind with the protein in a 1:1 molar ratio via a fraction of their hydrophobic pendant cholesterol resides along the polymer chain. In this protein/polymer complex, there are excess unbound cholesterol residues. As the polymer concentration increases, the polymers form multi-polymer aggregates around 200 nm in diameter via the same hydrophobic cholesterol residues. The protein/polymer complex also participate in the aggregation via their excess cholesterol residues, and consequently the proteins are encapsulated into the nanoparticles. The encapsulation was also found to increase the thermal stability of the model protein., Graphical abstract A physical picture is proposed for the interactions between proteins and hydrophobically-modified polypeptide, which can be a platform material for sustained release of protein drugs. The polymers form complexes with proteins via the hydrophobic interactions, and these protein-bound polymers self-assemble with other polymers to form nano-sized particles.fx1

The binding of adenomatous polyposis coli (APC) to its receptor Asef relieves the negative intramolecular regulation of Asef and leads to aberrant cell migration in human colorectal cancer. Because of its crucial role in metastatic dissemination, the interaction between APC and Asef is an attractive target for anti-colorectal-cancer therapy. We rationally designed a series of peptidomimetics that act as potent inhibitors of the APC interface. Crystal structures and biochemical and cellular assays showed that the peptidomimetics in the APC pocket inhibited the migration of colorectal cells by disrupting APC-Asef interaction. By using the peptidomimetic inhibitor as a chemical probe, we found that CDC42 was the downstream GTPase involved in APC-stimulated Asef activation in colorectal cancer cells. Our work demonstrates the feasibility of exploiting APC-Asef interaction to regulate the migration of colorectal cancer cells, and provides what to our knowledge is the first class of protein-protein interaction inhibitors available for the development of cancer therapeutics targeting APC-Asef signaling.

Catchment runoff scale relationships comprise an important theoretical support for water resource management. However, previous understandings of the scale effect were mostly based on empirical summaries and quantitative research, while interpretation based on measured data was rare. The purpose of this paper was to quantitatively reveal the causes of runoff scale impacts in the Haihe mountainous area over a 20-year period. Fifty-seven catchments (92-15803 km2) were selected from the available hydrological sites. Multi-year average values for17 environmental variables were calculated in each catchment over the study period, including data on hydrology, meteorology, vegetation, land use, topography, and soil. Based on these data, the quantitative relationship between runoff and catchment area was first established. Then the correlation between environmental factors and runoff scale impacts was assessed. Finally, catchments were divided into three groups by area, and the dominant factors influencing runoff at different scales, as well as the direct and indirect effects of these factors on runoff, were obtained using stepwise regression and path analysis. The results showed that: 1) Runoff coefficients decreased logarithmically as catchment area increased and the scale distribution characteristics of the variables closely related to runoff were an important reason for the runoff scale effect. 2) Larger river basins had fewer sensitivity factors for runoff and the impacts of vegetation and land use factors were mainly reflected in small and medium catchments. 3) Vegetation and land use primarily had indirect effects, which determined the proportion of factors in the total effect. Among these, the indirect effects of farmland were very prominent, which implied that human activities have had an important influence on runoff scale effects. This study emphasized the importance of farmland management in the upstream areas of Haihe mountainous area, and provides important theoretical support for catchment scale effects and water resource management in water-limited regions.

Mycobacterium tuberculosis (M.tb) is one of the most prevalent bacterial pathogens in the world. With geographical wide spread and hypervirulence, Beijing/W family is the most successful M.tb lineage. China is a country of high tuberculosis (TB) and high multiple drug-resistant TB (MDR-TB) burden, and the Beijing/W family strains take the largest share of MDR strains. To study the genetic basis of Beijing/W family strains' virulence and drug resistance, we performed the whole genome sequencing of M.tb strain W146, a clinical Beijing/W genotype MDR isolated from Wuxi, Jiangsu province, China. Compared with genome sequence of M.tb strain H37Rv, we found that strain W146 lacks three large fragments and the missing of furA-katG operon confers isoniazid resistance. Besides the missing of furA-katG operon, strain W146 harbored almost all known drug resistance-associated mutations. Comparison analysis of single nucleotide polymorphisms (SNPs) and indels between strain W146 and Beijing/W genotype strains and non-Beijing/W genotype strains revealed that strain W146 possessed some unique mutations, which may be related to drug resistance, transmission and pathogenicity. These findings will help to understand the large sequence polymorphisms (LSPs) and the transmission and drug resistance related genetic characteristics of the Beijing/W genotype of M.tb.

In colorectal cancer, adenomatous polyposis coli (APC) interacts with Rho guanine-nucleotide-exchange factor 4 (Asef), thereby stimulating aberrant colorectal-cancer-cell migration. Consequently, the APC–Asef interaction represents a promising therapeutic target for mitigating colorectal-cancer migration. In this study, we adopted the rational-design strategy involving the introduction of intramolecular hydrogen bonds and optimization of the lipophilic substituents to improve the binding affinities of peptides, leading to the discovery of MAI-400, the best inhibitor of the APC–Asef interaction known to date (Kd = 0.012 μM, IC50 = 0.25 μM). Comprehensive evaluation of MAI-400 by biochemical and biophysical assays revealed the formation and effect of an intramolecular hydrogen bond. A cell-based assay showed MAI-400 efficiently blocking the APC–Asef interaction in a dose-dependent manner. Therefore, our study provides a best-in-class inhibitor, MAI-400, based on the rational drug design and structural valid...

The aim of this work was to screen miRNA signatures dysregulated in tuberculosis to improve our understanding of the biological role of miRNAs involved in the disease. Datasets deposited in publically available databases from microarray studies on infectious diseases and malignancies were retrieved, screened, and subjected to further analysis. Effect sizes were combined using the inverse-variance model and between-study heterogeneity was evaluated by the random effects model. 35 miRNAs were differentially expressed (12 up-regulated, 23 down-regulated; p

Two series of bio-based poly(ether–ester)s from vanillic acid and linear α,ω-diols HO-(CH2)m-OH (m = 2, 3, 4, 10) have been successfully synthesized by the direct esterification method. These poly(ether–ester)s were characterized using FTIR, 1H-NMR, and size exclusion chromatography (SEC). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to study their thermo-mechanical properties. The poly(ether–ester)s had weight-average molecular weights (Mw) in the range of 16 600 to 78 700 g mol−1 and polydispersities between 1.39 and 2.00. All of the bio-based poly(ether–ester)s exhibited amorphous features with their glass transition temperatures (Tgs) ranging from 5 to 67 °C. The stress–strain parameters showed that the mechanical properties of these poly(ether–ester)s were excellent. The Young's modulus and elongation at break of the poly(ether–ester)s in this series were found to be in the range of 95–228 MPa and 14.9–311%, respectively.

DNA replication initiation is a central event in the cell cycle, and it is strictly controlled by multiple regulatory mechanisms. Our previous work showed that acetylation of residue lysine (K) 178 prevents DnaA from binding to ATP, which leads to the inhibition of DNA replication initiation. Here, we show that another residue, K243, is critical for DnaA full activity in vivo. K243 can be acetylated, and its acetylation level varies with cell growth. A homogeneous, recombinant DnaA that contains N𝜀-acetyllysine at K243 (K243Ac) retained its ATP/ADP binding ability, but showed decreased binding activity to the oriC region. A DNase I footprinting assay showed that DnaA K243Ac failed to recognize DnaA boxes I3, C1, and C3, and, thus, it formed an incomplete initiation complex with oriC. Finally, we found that acetyl phosphate and the deacetylase CobB can regulate the acetylation level of K243 in vivo. These findings suggest that DnaA K243 acetylation disturbs its binding to low-affinity DnaA boxes, and they provide new insights into the regulatory mechanisms of DNA replication initiation.

Enterohemorrhagic Escherichia coli (EHEC) is one major type of contagious and foodborne pathogens. The type VI secretion system (T6SS) has been shown to be involved in the bacterial pathogenicity and bacteria-bacteria competition. Here, we show that EHEC could secrete a novel effector KatN, a Mn-containing catalase, in a T6SS-dependent manner. Expression of katN is promoted by RpoS and OxyR and repressed by H-NS, and katN contributes to bacterial growth under oxidative stress in vitro. KatN could be secreted into host cell cytosol after EHEC is phagocytized by macrophage, which leads to decreased level of intracellular reactive oxygen species (ROS) and facilitates the intramacrophage survival of EHEC. Finally, animal model results show that the deletion mutant of T6SS was attenuated in virulence compared with the wild type strain, while the deletion mutant of katN had comparable virulence to the wild type strain. Taken together, our findings suggest that EHEC could sense oxidative stress in phagosome and decrease the host cell ROS by secreting catalase KatN to facilitate its survival in the host cells., Author summary The type VI secretion system (T6SS) is a specific macromolecular protein export apparatus, and widely distributed in Gram-negative bacteria. Generally, T6SS has been shown to play an important role in anti-bacterial competition and virulence to eukaryotic hosts. Enterohemorrhagic Escherichia coli (EHEC) can cause severe foodborne disease, including abdominal cramps and diarrhea that may progress to bloody diarrhea and hemolytic uremic syndrome. In the current study, we show that the T6SS of EHEC is involved in its intracellular survival and virulence in mice. Specifically, the novel effector KatN, a Mn-catalase identified in this work updates the general role of the T6SS in the pathogenesis of EHEC, in the context of oxidative stress in host cytoplasm. Combined with the biased distribution of katN in the T6SS-containing bacteria, our data suggest that KatN, as a new T6SS effector, is a key virulence factor in the pathogenesis of T6SS+ bacteria.

The regulation of chromosomal replication is critical and the activation of DnaA by ATP binding is a key step in replication initiation. However, it remains unclear whether and how the process of ATP-binding to DnaA is regulated. Here, we show that DnaA can be acetylated and its acetylation level varies with cell growth and correlates with DNA replication initiation frequencies in E. coli. Specifically, the conserved K178 in Walker A motif of DnaA can be acetylated and its acetylation level reaches the summit at the stationary phase, which prevents DnaA from binding to ATP or oriC and leads to inhibition of DNA replication initiation. The deacetylation process of DnaA is catalyzed by deacetylase CobB. The acetylation process of DnaA is mediated by acetyltransferase YfiQ and nonenzymatically by acetyl-phosphate. These findings suggest that the reversible acetylation of DnaA ensures cells to respond promptly to environmental changes. Since Walker A motif is universally distributed across organisms, acetylation of Walker A motif may present a novel regulatory mechanism conserved from bacteria to eukaryotes.