2r82

From Proteopedia

---

Revision as of 09:20, 23 January 2008

proteopedia linkproteopedia link

spinqualitylabelsall models 2r82, resolution 3.6Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Pyruvate phosphate dikinase (PPDK) triple mutant R219E/E271R/S262D adapts a second conformational state

Overview

Crystals of pyruvate phosphate dikinase in complex with a substrate, analogue inhibitor, phosphonopyruvate (K(i) = 3 microM), have been, obtained in the presence of Mg(2+). The structure has been determined and, refined at 2.2 A resolution, revealing that the Mg(2+)-bound, phosphonopyruvate binds in the alpha/beta-barrel's central channel, at the, C-termini of the beta-strands. The mode of binding resembles closely the, previously proposed PEP substrate binding mode, inferred by the homology, of the structure (but not sequence homology) to pyruvate kinase. Kinetic, analysis of site-directed mutants, probing residues involved in inhibitor, binding, showed that all mutations resulted in inactivation, confirming, the key role that these residues play in catalysis. Comparison between the, structure of the PPDK-phosphonopyruvate complex and the structures of two, complexes of pyruvate kinase, one with Mg(2+)-bound phospholactate and the, other with Mg(2+)-oxalate and ATP, revealed that the two enzymes share, some key features that facilitate common modes of substrate binding. There, are also important structural differences; most notably, the machinery for, acid/base catalysis is different.

About this Structure

2R82 is a Single protein structure of sequence from Clostridium symbiosum with as ligand. Active as Pyruvate, phosphate dikinase, with EC number 2.7.9.1 Full crystallographic information is available from OCA.

Reference

Pyruvate site of pyruvate phosphate dikinase: crystal structure of the enzyme-phosphonopyruvate complex, and mutant analysis., Herzberg O, Chen CC, Liu S, Tempczyk A, Howard A, Wei M, Ye D, Dunaway-Mariano D, Biochemistry. 2002 Jan 22;41(3):780-7. PMID:11790099

Page seeded by OCA on Wed Jan 23 11:20:00 2008