1yvy
From Proteopedia
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Crystal strucutre of Anaerobiospirillum succiniciproducens phosphoenolpyruvate carboxykinase
Overview
The 2.2 Angstroms resolution crystal structure of the enzyme, phosphoenolpyruvate carboxykinase (PCK) from the bacterium, Anaerobiospirillum succiniciproducens complexed with ATP, Mg(2+), Mn(2+), and the transition state analogue oxalate has been solved. The 2.4, Angstroms resolution native structure of A. succiniciproducens PCK has, also been determined. It has been found that upon binding of substrate, PCK undergoes a conformational change. Two domains of the molecule fold, towards each other, with the substrates and metal ions held in a cleft, formed between the two domains. This domain movement is believed to, accelerate the reaction PCK catalyzes by forcing bulk solvent molecules, out of the active site. Although the crystal structure of A., succiniciproducens PCK with bound substrate and metal ions is related to, the structures of PCK from Escherichia coli and Trypanosoma cruzi, it is, the first crystal structure from this class of enzymes that clearly shows, an important surface loop (residues 383-397) from the C-terminal domain, hydrogen bonding with the peptide backbone of the active site residue, Arg60. The interaction between the surface loop and the active site, backbone, which is a parallel beta-sheet, seems to be a feature unique of, A. succiniciproducens PCK. The association between the loop and the active, site is the third type of interaction found in PCK that is thought to play, a part in the domain closure. This loop also appears to help accelerate, catalysis by functioning as a 'lid' that shields water molecules from the, active site.
About this Structure
1YVY is a Single protein structure of sequence from Anaerobiospirillum succiniciproducens. Active as Phosphoenolpyruvate carboxykinase (ATP), with EC number 4.1.1.49 Full crystallographic information is available from OCA.
Reference
Crystal structure of Anaerobiospirillum succiniciproducens PEP carboxykinase reveals an important active site loop., Cotelesage JJ, Prasad L, Zeikus JG, Laivenieks M, Delbaere LT, Int J Biochem Cell Biol. 2005 Sep;37(9):1829-37. PMID:15890557
Page seeded by OCA on Wed Nov 21 07:05:30 2007
