Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Structural basis for allosteric regulation of mycobacterial guanosine 5´-monophosphate reductase by ATP and GTP.
Journal, issue, pages	Nat Commun, Vol. 17, Issue 1, Year 2026
Publish date	Apr 13, 2026
Authors	Michal Doležal / Zdeněk Knejzlík / Tomáš Kouba / Anatolij Filimoněnko / Hana Šváchová / Matteo Dedola / Martin Klíma / Iva Pichová /
PubMed Abstract	Guanosine 5'-monophosphate reductase (GMPR) is a crucial enzyme in the purine salvage pathway that catalyses the NADPH-dependent conversion of GMP to IMP, thereby contributing to purine nucleotide ...Guanosine 5'-monophosphate reductase (GMPR) is a crucial enzyme in the purine salvage pathway that catalyses the NADPH-dependent conversion of GMP to IMP, thereby contributing to purine nucleotide homeostasis. Mycobacterium smegmatis GMPR (MsmGMPR) contains a regulatory cystathionine β-synthase (CBS) domain, which mediates allosteric modulation by ATP and GTP. However, MsmGMPR exhibits an atypical tertiary structure that is incompatible with the acknowledged regulatory mechanisms of IMPDH/GMPR family enzymes. Here, we combine X-ray crystallography, cryogenic electron microscopy, and biochemical binding assays to elucidate the molecular basis of MsmGMPR regulation by ATP and GTP. We show that ATP stabilises a compressed conformation that inhibits the enzyme by restricting access to the active site and preventing NADPH binding. In contrast, GTP counteracts ATP binding, promoting an active conformation that enables catalysis. Our results provide insight into how MsmGMPR senses and responds to the purine nucleotide balance, revealing a distinct utilisation of the CBS domain compared with its typical role in IMPDH/GMPR enzymes.
External links	Nat Commun / PubMed:41974687 / PubMed Central
Methods	EM (single particle) / X-ray diffraction
Resolution	1.6 - 3.85 Å
Structure data	19583 8ry0 EMDB-19583, PDB-8ry0: CryoEM structure of M. smegmatis GMP reductase in complex with GMP at pH 6.6, extended conformation. Method: EM (single particle) / Resolution: 3.66 Å 19584 8ry1 EMDB-19584, PDB-8ry1: CryoEM structure of M. smegmatis GMP reductase in complex with GMP at pH 6.6, compressed conformation. Method: EM (single particle) / Resolution: 3.85 Å 19585 8ry3 EMDB-19585, PDB-8ry3: CryoEM structure of M. smegmatis GMP reductase in complex with GMP and GTP at pH 6.6, extended conformation I. Method: EM (single particle) / Resolution: 2.52 Å 19586 8ry4 EMDB-19586, PDB-8ry4: CryoEM structure of M. smegmatis GMP reductase in complex with GMP and GTP at pH 6.6, extended conformation II. Method: EM (single particle) / Resolution: 3.72 Å 19587 8ry5 EMDB-19587, PDB-8ry5: CryoEM structure of M. smegmatis GMP reductase in complex with GMP and ATP at pH 6.6, compressed conformation. Method: EM (single particle) / Resolution: 2.48 Å 19588 8ry6 EMDB-19588, PDB-8ry6: CryoEM structure of M. smegmatis GMP reductase apoform at pH 6.6, extended conformation I. Method: EM (single particle) / Resolution: 3.22 Å 19589 8ry7 EMDB-19589, PDB-8ry7: CryoEM structure of M. smegmatis GMP reductase apoform at pH 6.6, extended conformation II. Method: EM (single particle) / Resolution: 3.7 Å 19590 8ry8 EMDB-19590, PDB-8ry8: CryoEM structure of M. smegmatis GMP reductase apoform at pH 7.8, extended conformation I. Method: EM (single particle) / Resolution: 2.96 Å 19591 8ry9 EMDB-19591, PDB-8ry9: CryoEM structure of M. smegmatis GMP reductase apoform at pH 7.8, extended conformation II. Method: EM (single particle) / Resolution: 3.2 Å 19592 8rya EMDB-19592, PDB-8rya: CryoEM structure of M. smegmatis GMP reductase apoform at pH 7.8, tetramer. Method: EM (single particle) / Resolution: 2.82 Å 19593 8ryb EMDB-19593, PDB-8ryb: CryoEM structure of M. smegmatis GMP reductase in complex with GMP at pH 7.8, extended conformation. Method: EM (single particle) / Resolution: 2.84 Å PDB-9hfz: Crystal structure of M. smegmatis GMP reductase in complex with IMP. Method: X-RAY DIFFRACTION / Resolution: 2.8 Å PDB-9hg0: Crystal structure of M. smegmatis GMP reductase *with XMP intermidiate in complex with NADP+ and IMP. Method: X-RAY DIFFRACTION / Resolution: 2.1 Å PDB-9hg1: Crystal structure of M. smegmatis GMP reductase in complex with GMP and ATP. Method: X-RAY DIFFRACTION / Resolution: 2.3 Å PDB-9hg2: Crystal structure of M. smegmatis GMP reductase in complex with IMP and ATP. Method: X-RAY DIFFRACTION / Resolution: 1.6 Å PDB-9hg3: Crystal structure of M. smegmatis GMP reductase in complex with GMP and GTP. Method: X-RAY DIFFRACTION / Resolution**: 2.3 Å
Chemicals	ChemComp-5GP: GUANOSINE-5'-MONOPHOSPHATE ChemComp-GTP: GUANOSINE-5'-TRIPHOSPHATE / GTP, energy-carrying moleculeYM ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP, energy-carrying moleculeYM ChemComp-HOH: WATER ChemComp-IMP: INOSINIC ACID ChemComp-NAP: NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
Source	mycolicibacterium smegmatis (bacteria)
Keywords	OXIDOREDUCTASE / GMP reductase / GuaB1 / CBS domain / Mycobacterium smegmatis