1nba

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1nba, resolution 2.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE ANALYSIS, REFINEMENT AND ENZYMATIC REACTION MECHANISM OF N-CARBAMOYLSARCOSINE AMIDOHYDROLASE FROM ARTHROBACTER SP. AT 2.0 ANGSTROMS RESOLUTION

Overview

N-carbamoylsarcosine amidohydrolase from Arthrobacter sp., a tetramer of, polypeptides with 264 amino acid residues each, has been crystallized and, its structure solved and refined at 2.0 A resolution, to a, crystallographic R-factor of 18.6%. The crystals employed in the analysis, contain one tetramer of 116,000 M(r) in the asymmetric unit. The structure, determination proceeded by multiple isomorphous replacement, followed by, solvent-flattening and density averaging about the local diads within the, tetramer. In the final refined model, the root-mean-square deviation from, ideality is 0.01 A for bond distances and 2.7 degrees for bond angles. The, asymmetric unit consists of 7853 protein atoms, 431 water molecules and, four sulfate ions bound into the putative active site clefts in each, subunit. One subunit contains a central six-stranded parallel beta-pleated, sheet packed by helices on both sides. On one side, two helices face the, solvent, while two of the helices on the other side are buried in the, tight intersubunit contacts. The catalytic center of the enzyme, tentatively identified by inhibitor binding, is located at the interface, between two subunits and involves residues from both. It is suggested that, the nucleophilic group involved in hydrolysis of the substrate is the, thiol group of Cys117 and a nucleophilic addition-elimination mechanism is, proposed.

About this Structure

1NBA is a Single protein structure of sequence from Arthrobacter sp. with SO4 as ligand. Active as N-carbamoylsarcosine amidase, with EC number 3.5.1.59 Full crystallographic information is available from OCA.

Reference

Crystal structure analysis, refinement and enzymatic reaction mechanism of N-carbamoylsarcosine amidohydrolase from Arthrobacter sp. at 2.0 A resolution., Romao MJ, Turk D, Gomis-Ruth FX, Huber R, Schumacher G, Mollering H, Russmann L, J Mol Biol. 1992 Aug 20;226(4):1111-30. PMID:1381445

Page seeded by OCA on Tue Nov 20 22:06:46 2007