1ECC

ESCHERICHIA COLI GLUTAMINE PHOSPHORIBOSYLPYROPHOSPHATE (PRPP) AMIDOTRANSFERASE COMPLEXED WITH MN-CPRPP AND 5-OXO-NORLEUCINE

Summary for 1ECC

• Entry DOI: 10.2210/pdb1ecc/pdb
• Descriptor: GLUTAMINE PHOSPHORIBOSYLPYROPHOSPHATE AMIDOTRANSFERASE, MANGANESE (II) ION, 5-OXO-L-NORLEUCINE, ... (5 entities in total)
• Functional Keywords: transferase, glutamine amidotransferase, purine biosynthesis, glycosyltransferase
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 114186.56

Authors

Krahn, J.M.,Smith, J.L. (deposition date: 1997-07-09, release date: 1998-04-15, Last modification date: 2023-08-09)

Primary citation

Krahn, J.M.,Kim, J.H.,Burns, M.R.,Parry, R.J.,Zalkin, H.,Smith, J.L.
Coupled formation of an amidotransferase interdomain ammonia channel and a phosphoribosyltransferase active site.
Biochemistry, 36:11061-11068, 1997

PubMed Abstract: 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.

PubMed: 9333323
DOI: 10.1021/bi9714114

Experimental method

X-RAY DIFFRACTION (2.4 Å)