1bgv
From Proteopedia
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GLUTAMATE DEHYDROGENASE
Overview
We have solved the structure of the binary complex of the glutamate, dehydrogenase from Clostridium symbiosum with glutamate to 1.9 A, resolution. In this complex, the glutamate side-chain lies in a pocket on, the enzyme surface and a key determinant of the enzymic specificity is an, interaction of the substrate gamma-carboxyl group with the amino group of, Lys89. In the apo-enzyme, Lys113 from the catalytic domain forms an, important hydrogen bond to Asn373, in the NAD(+)-binding domain. On, glutamate binding, the side-chain of this lysine undergoes a significant, movement in order to optimize its hydrogen bonding to the alpha-carboxyl, group of the substrate. Despite this shift, the interaction between Lys113, and Asn373 is maintained by a large-scale conformational change that, closes the cleft between the two domains. Modelling studies indicate that, in this "closed" conformation the C-4 of the nicotinamide ring and the, alpha-carbon atom of the amino acid substrate are poised for efficient, hydride transfer. Examination of the structure has led to a proposal for, the catalytic activity of the enzyme, which involves Asp165 as a general, base, and an enzyme-bound water molecule, hydrogen-bonded to an uncharged, lysine residue, Lys125, as an attacking nucleophile in the reaction.
About this Structure
1BGV is a Single protein structure of sequence from Clostridium symbiosum with GLU as ligand. Active as Glutamate dehydrogenase, with EC number 1.4.1.2 Full crystallographic information is available from OCA.
Reference
Conformational flexibility in glutamate dehydrogenase. Role of water in substrate recognition and catalysis., Stillman TJ, Baker PJ, Britton KL, Rice DW, J Mol Biol. 1993 Dec 20;234(4):1131-9. PMID:8263917
Page seeded by OCA on Tue Nov 20 11:38:54 2007
