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NAD + biosynthesis in bacteria is controlled by global carbon/nitrogen levels via PII signaling.

Authors :
Santos ARS
Gerhardt ECM
Parize E
Pedrosa FO
Steffens MBR
Chubatsu LS
Souza EM
Passaglia LMP
Sant'Anna FH
de Souza GA
Huergo LF
Forchhammer K
Source :
The Journal of biological chemistry [J Biol Chem] 2020 May 01; Vol. 295 (18), pp. 6165-6176. Date of Electronic Publication: 2020 Mar 16.
Publication Year :
2020

Abstract

NAD <superscript>+</superscript> is a central metabolite participating in core metabolic redox reactions. The prokaryotic NAD synthetase enzyme NadE catalyzes the last step of NAD <superscript>+</superscript> biosynthesis, converting nicotinic acid adenine dinucleotide (NaAD) to NAD <superscript>+</superscript> Some members of the NadE family use l-glutamine as a nitrogen donor and are named NadE <superscript>Gln</superscript> Previous gene neighborhood analysis has indicated that the bacterial nadE gene is frequently clustered with the gene encoding the regulatory signal transduction protein PII, suggesting a functional relationship between these proteins in response to the nutritional status and the carbon/nitrogen ratio of the bacterial cell. Here, using affinity chromatography, bioinformatics analyses, NAD synthetase activity, and biolayer interferometry assays, we show that PII and NadE <superscript>Gln</superscript> physically interact in vitro , that this complex relieves NadE <superscript>Gln</superscript> negative feedback inhibition by NAD <superscript>+</superscript> This mechanism is conserved in distantly related bacteria. Of note, the PII protein allosteric effector and cellular nitrogen level indicator 2-oxoglutarate (2-OG) inhibited the formation of the PII-NadE <superscript>Gln</superscript> complex within a physiological range. These results indicate an interplay between the levels of ATP, ADP, 2-OG, PII-sensed glutamine, and NAD <superscript>+</superscript> , representing a metabolic hub that may balance the levels of core nitrogen and carbon metabolites. Our findings support the notion that PII proteins act as a dissociable regulatory subunit of NadE <superscript>Gln</superscript> , thereby enabling the control of NAD <superscript>+</superscript> biosynthesis according to the nutritional status of the bacterial cell.<br /> (© 2020 Santos et al.)

Details

Language :
English
ISSN :
1083-351X
Volume :
295
Issue :
18
Database :
MEDLINE
Journal :
The Journal of biological chemistry
Publication Type :
Academic Journal
Accession number :
32179648
Full Text :
https://doi.org/10.1074/jbc.RA120.012793