1ecb

ESCHERICHIA COLI GLUTAMINE PHOSPHORIBOSYLPYROPHOSPHATE (PRPP) AMIDOTRANSFERASE COMPLEXED WITH 2 GMP, 1 MG PER SUBUNIT

spinqualitylabelsall models 1ecb, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ecb is a 4 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 5GP, MG Activity: Amidophosphoribosyltransferase, with EC number 2.4.2.14 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 PubMed Activation of gluatmine phosphoribosylpyrophosphate (RPPP) amidotransferase (GPATase) by binding of a PRPP substrate analog results in the formation of a 20 A channel connecting the active site for glutamine hydrolysis in one domain with the PRPP site in a second domain. This solvent-inaccessible channel permits transfer of the NH3 intermediate between the two active sites. Tunneling of NH3 may be a common mechanism for glutamine amidotransferase-catalyzed nitrogen transfer and for coordination of catalysis at two distinct active sites in complex enzymes. The 2.4 A crystal structure of the active conformer of GPATase also provides the first description of an intact active site for the phosphoribosyltransferase (PRTase) family of nucleotide synthesis and salvage enzymes. Chemical assistance to catalysis is provided primarily by the substrate and secondarily by the enzyme in the proposed structure-based mechanism. Different catalytic and inhibitory modes of divalent cation binding to the PRTase active site are revealed in the active conformer of the enzyme and in a feedback-inhibited GMP complex. Coupled formation of an amidotransferase interdomain ammonia channel and a phosphoribosyltransferase active site.,Krahn JM, Kim JH, Burns MR, Parry RJ, Zalkin H, Smith JL Biochemistry. 1997 Sep 16;36(37):11061-8. PMID:9333323 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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