1ecf
From Proteopedia
|
ESCHERICHIA COLI GLUTAMINE PHOSPHORIBOSYLPYROPHOSPHATE (PRPP) AMIDOTRANSFERASE
Overview
Crystal structures of glutamine phosphoribosylpyrophosphate (PRPP), amidotransferase from Escherichia coli have been determined to 2.0-A, resolution in the absence of ligands, and to 2.5-A resolution with the, feedback inhibitor AMP bound to the PRPP catalytic site. Glutamine PRPP, amidotransferase (GPATase) employs separate catalytic domains to abstract, nitrogen from the amide of glutamine and to transfer nitrogen to the, acceptor substrate PRPP. The unliganded and AMP-bound structures, which, are essentially identical, are interpreted as the inhibited form of the, enzyme because the two active sites are disconnected and the PRPP active, site is solvent exposed. The structures were compared with a previously, reported 3.0-A structure of the homologous Bacillus subtilis enzyme (Smith, JL et al., 1994, Science 264:1427-1433). The comparison indicates a, pattern of conservation of peptide structures involved with catalysis and, variability in enzyme regulatory functions. Control of glutaminase, activity, communication between the active sites, and regulation by, feedback inhibitors are addressed differently by E. coli and B. subtilis, GPATases. The E. coli enzyme is a prototype for the metal-free GPATases, whereas the B. subtilis enzyme represents the metal-containing enzymes., The structure of the E. coli enzyme suggests that a common ancestor of the, two enzyme subfamilies may have included an Fe-S cluster.
About this Structure
1ECF is a Single protein structure of sequence from Escherichia coli with PIN as ligand. Active as Amidophosphoribosyltransferase, with EC number 2.4.2.14 Full crystallographic information is available from OCA.
Reference
Crystal structure of glutamine phosphoribosylpyrophosphate amidotransferase from Escherichia coli., Muchmore CR, Krahn JM, Kim JH, Zalkin H, Smith JL, Protein Sci. 1998 Jan;7(1):39-51. PMID:9514258
Page seeded by OCA on Tue Nov 20 13:53:35 2007
