1. The mycobacterial guaB1 gene encodes a guanosine 5'-monophosphate reductase with a cystathionine-β-synthase domain.
- Author
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Knejzlík Z, Doležal M, Herkommerová K, Clarova K, Klíma M, Dedola M, Zborníková E, Rejman D, and Pichová I
- Subjects
- Adenosine Triphosphate, Cystathionine beta-Synthase genetics, GMP Reductase genetics, GMP Reductase metabolism, Guanosine Monophosphate metabolism, Guanosine Triphosphate, IMP Dehydrogenase genetics, IMP Dehydrogenase metabolism, Inosine, Inosine Monophosphate metabolism, Cystathionine, Mycobacterium tuberculosis metabolism
- Abstract
Mycobacteria express enzymes from both the de novo and purine-salvage pathways. However, the regulation of these processes and the roles of individual metabolic enzymes have not been sufficiently detailed. Both Mycobacterium tuberculosis (Mtb) and Mycobacterium smegmatis (Msm) possess three guaB genes, but information is only available on guaB2, which encodes an essential inosine 5'-monophosphate dehydrogenase (IMPDH) involved in de novo purine biosynthesis. This study shows that guaB1, annotated in databases as a putative IMPDH, encodes a guanosine 5'-monophosphate reductase (GMPR), which recycles guanosine monophosphate to inosine monophosphate within the purine-salvage pathway and contains a cystathionine-β-synthase domain (CBS), which is essential for enzyme activity. GMPR activity is allosterically regulated by the ATP/GTP ratio in a pH-dependent manner. Bioinformatic analysis has indicated the presence of GMPRs containing CBS domains across the entire Actinobacteria phylum., (© 2022 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Published
- 2022
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