Crystal structure of guanosine 5'-monophosphate synthetase from the thermophilic bacterium Thermus thermophilus HB8.

Autor: Nemoto N; Faculty of Advanced Engineering, Chiba Institute of Technology, Narashino, Chiba 275-0016, Japan., Baba S; RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan., Kawai G; Faculty of Advanced Engineering, Chiba Institute of Technology, Narashino, Chiba 275-0016, Japan., Sampei GI; Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Jazyk: angličtina
Zdroj: Acta crystallographica. Section F, Structural biology communications [Acta Crystallogr F Struct Biol Commun] 2024 Oct 01; Vol. 80 (Pt 10), pp. 278-285. Date of Electronic Publication: 2024 Sep 18.
DOI: 10.1107/S2053230X2400877X
Abstrakt: Guanosine 5'-monophosphate (GMP) synthetase (GuaA) catalyzes the last step of GMP synthesis in the purine nucleotide biosynthetic pathway. This enzyme catalyzes a reaction in which xanthine 5'-monophosphate (XMP) is converted to GMP in the presence of Gln and ATP through an adenyl-XMP intermediate. A structure of an XMP-bound form of GuaA from the domain Bacteria has not yet been determined. In this study, the crystal structure of an XMP-bound form of GuaA from the thermophilic bacterium Thermus thermophilus HB8 (TtGuaA) was determined at a resolution of 2.20 Å and that of an apo form of TtGuaA was determined at 2.10 Å resolution. TtGuaA forms a homodimer, and the monomer is composed of three domains, which is a typical structure for GuaA. Disordered regions in the crystal structure were obtained from the AlphaFold2-predicted model structure, and a model with substrates (Gln, XMP and ATP) was constructed for molecular-dynamics (MD) simulations. The structural fluctuations of the TtGuaA dimer as well as the interactions between the active-site residues were analyzed by MD simulations.
(open access.)
Databáze: MEDLINE
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