Conformational changes involving ammonia tunnel formation and allosteric control in GMP synthetase.

ABSTRACT: GMP synthetase is the glutamine amidotransferase that catalyzes the final step in the guanylate branch of de novo purine biosynthesis. Conformational changes are required to efficiently couple distal active sites in the protein; however, the nature of these changes has remained elusive. Structural information derived from both limited proteolysis and sedimentation velocity experiments support the hypothesis of nucleotide-induced loop- and domain-closure in the protein. These results were combined with information from sequence conservation and precedents from other glutamine amidotransferases to develop the first structural model of GMPS in a closed, active state. In analyzing this Catalytic model, an interdomain salt bridge was identified residing in the same location as seen in other tri

SUBMITTER: Oliver JC 

PROVIDER: S-EPMC3954777 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature