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[Display omitted] • CA domain of bacterial HKs presents a novel anti-virulence or antibiotic target. • CA domain targeted molecules can inhibit multiple HKs, increasing effectiveness. • Structural data suggests several key conserved residues involved in inhibition. • Selectivity over eukaryotic kinases and other GHKL proteins is possible. With the rise in antimicrobial resistance and the dearth of effective strategies to combat this threat, the development of novel therapies is of utmost importance. Targeting of bacterial signaling through their the two-component systems (TCSs) may be a viable strategy. TCSs are comprised of a sensory histidine kinase (HK), of which a bacterium can have up to 160 distinct proteins, and a cognate response regulator (RR). The TCSs are generally non-essential for life, but control many virulence and antibiotic-resistance mechanisms. This, along with their absence in animals makes the TCSs an attractive target for antimicrobial therapy, whether as a stand-alone treatments or adjuvants for existing therapies. This review focuses on progress in the development of inhibitors that target the HK ATP-binding domain. Because this domain is highly conserved, it may be feasible to disrupt multiple TCSs within a single organism to increase effectiveness and reduce pressure for the evolution of resistance. [ABSTRACT FROM AUTHOR]

Bacteria comprise complex communities within our bodies and largely have beneficial roles, however a small percentage are pathogenic. While all pathogens are important to public health, immediate action is necessary to combat bacterial strains developing pan- and multi-resistance to antibiotics. As present therapeutics fail to tackle this problem, novel strategies are required to address this threat. Activity-based probes (ABPs) are one method to investigate proteins of interest in pathogens. These probes can serve multiple purposes to better our understanding of bacterial pathogenicity. Herein, we highlight recent studies that used ABPs to identify new drug targets or visualize antibiotic resistance- or bacterial virulence-associated proteins, and introduce strategies to determine the specificity of ABPs within a targeted enzyme class. [Display omitted] [ABSTRACT FROM AUTHOR]

Secondary metabolite discovery from bacteria has become increasingly successful in the last decade due to the advancement of integrated genetic-based, spectrometric-based and informatics-based techniques. Microbes and their unique metabolic outputs have been widely studied since the beginning of modern medicine; however, it is well known that the current repertoire of secondary metabolites, or more commonly natural products, is incomplete and the understanding of natural product-mediated intracellular dialog is in its infancy. Here, we highlight the present state of bacterial metabolomics including compound discovery approaches and new strategies for probing the role of these molecules within communication networks. [ABSTRACT FROM AUTHOR]

Abstract: The affinity of silicon for oxygen has long been exploited to preferentially react hydroxyl moieties in the presence of others. Here, we explore the ability of a variety of dialkylsiloxane-functionalized resins to selectively capture and subsequently, release alcohol-containing compounds based on the steric environment about the silicon and hydroxyl moiety. The devised reagents will be applicable to the separation of compound mixtures, especially for the selective enrichment of low abundant molecules such as bioactive natural products. [Copyright &y& Elsevier]

Chemoselective purification technologies have seen great success in biomolecule isolation, with a classic example being the genetically-encoded His tag utilized to enrich desired proteins from a crude lysate. We sought to translate this purification tactic into a powerful tool for the isolation of natural products and demonstrate that chemoselective enrichment can reduce the number of purification steps required and increase the yield obtained for important natural products, as compared to the use of traditional chromatography methods alone. To date, we have reported reversible enrichment tags for three functional groups, carboxylic acids and aliphatic or aryl hydroxyls. To illustrate the power of chemoselectivity-mediated purification of natural products, we present here an improved isolation of borrelidin. Application of our carboxylic acid tag yielded pure borrelidin in only two steps and with double the yield acquired with traditional chromatography methods. These results highlight the utility of this orthogonal strategy to facilitate the isolation of natural products, which are often present in minute quantities in their source materials. [ABSTRACT FROM AUTHOR]

Molecular imaging methods to visualize myriad biochemical processes in bacteria have traditionally been dependent upon molecular biology techniques to incorporate fluorescent biomolecules (e.g., fusion proteins). Such methods have been instrumental in our understanding of how bacteria function but are not without drawbacks, including potential perturbation to native protein expression and function. To overcome these limitations, the use of fluorescent small-molecule probes has gained much attention. Here, we highlight examples from the recent literature that showcase the utility of small-molecule probes for the fluorescence imaging of bacterial cells, including electrophilic, metabolic, and enzyme-activated probes. Although the use of these types of compounds for bacterial imaging is still relatively new, the selected examples demonstrate the exciting potential of these critical tools in the exploration of bacterial physiology. Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Histidine kinases of bacterial two-component systems are promising antibacterial targets. Despite their varied, numerous roles, enzymes in the histidine kinase superfamily share a catalytic core that may be exploited to inhibit multiple histidine kinases simultaneously. Characterized by the Bergerat fold, the features of the histidine kinase ATP-binding domain are not found in serine/threonine and tyrosine kinases. However, because each kinase family binds the same ATP substrate, we sought to determine if published serine/threonine and tyrosine kinase inhibitors contained scaffolds that would also inhibit histidine kinases. Using select assays, 222 inhibitors from the Roche Published Kinase Set were screened for binding, deactivation, and aggregation of histidine kinases. Not only do the results of our screen support the distinctions between ATP-binding domains of different kinase families, but the lead molecule identified also presents inspiration for further histidine kinase inhibitor development. [ABSTRACT FROM AUTHOR]

Pretherapy patients with chronic lymphocytic leukemia (CLL) from US Intergroup trial E2997 were analyzed with single nucleotide polymorphism microarrays to detect acquired chromosomal anomalies. The four CLL-typical anomalies (11q-, +12, 13q-, and 17p-) were found at expected frequencies. Acquired anomalies in other regions account for 70% of the total detected anomalies, and their number per participant has a significant effect on progression-free survival after adjusting for the effects of 17p- (and other covariates). These results were compared with those from a previous study of more than 50,000 participants from the GENEVA consortium of genome-wide association studies, which analyzed individuals with a variety of medical conditions and healthy controls. The percentage of individuals with acquired anomalies is vastly different between the two studies (GENEVA 0.8%; E2997 80%). The composition of the anomalies also differs, with GENEVA having a higher percentage of acquired uniparental disomies and a lower percentage of deletions. The four common CLL anomalies are among the most frequent in GENEVA participants, some of whom may have CLL-precursor conditions or early stages of CLL. However, the patients from E2997 (and other studies of symptomatic CLL) have recurrent acquired anomalies that were not found in GENEVA participants, thus identifying genomic changes that may be unique to symptomatic stages of CLL. [Copyright &y& Elsevier]