1vcn
From Proteopedia
Crystal Structure of T.th. HB8 CTP synthetase complex with Sulfate anion
Structural highlights
FunctionPYRG_THET8 Catalyzes the ATP-dependent amination of UTP to CTP with either L-glutamine or ammonia as the source of nitrogen (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCTP synthetase (CTPs) catalyzes the last step in CTP biosynthesis, in which ammonia generated at the glutaminase domain reacts with the ATP-phosphorylated UTP at the synthetase domain to give CTP. Glutamine hydrolysis is active in the presence of ATP and UTP and is stimulated by the addition of GTP. We report the crystal structures of Thermus thermophilus HB8 CTPs alone, CTPs with 3SO4(2-), and CTPs with glutamine. The enzyme is folded into a homotetramer with a cross-shaped structure. Based on the binding mode of sulfate anions to the synthetase site, ATP and UTP are computer modeled into CTPs with a geometry favorable for the reaction. Glutamine bound to the glutaminase domain is situated next to the triad of Glu-His-Cys as a catalyst and a water molecule. Structural information provides an insight into the conformational changes associated with the binding of ATP and UTP and the formation of the GTP binding site. Crystal structures of CTP synthetase reveal ATP, UTP, and glutamine binding sites.,Goto M, Omi R, Nakagawa N, Miyahara I, Hirotsu K Structure. 2004 Aug;12(8):1413-23. PMID:15296735[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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