1VCO: Crystal Structure Of T.Th. Hb8 Ctp Synthetase Complex With Glutamine

CTP 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.
PDB ID: 1VCODownload
MMDB ID: 29178
PDB Deposition Date: 2004/3/10
Updated in MMDB: 2012/10
Experimental Method:
x-ray diffraction
Resolution: 2.15  Å
Source Organism:
Similar Structures:
Biological Unit for 1VCO: tetrameric; determined by author
Molecular Components in 1VCO
Label Count Molecule
Proteins (4 molecules)
CTP Synthetase(Gene symbol: pyrG)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB