1qwj

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models PDB ID 1qwj Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
, resolution 2.8Å
Ligands:
Gene:	Cmas (Mus musculus)
Activity:	N-acylneuraminate cytidylyltransferase, with EC number 2.7.7.43
Related:	1EYR, 1GQC
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase

Overview

Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation.

About this Structure

1QWJ is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.

Reference

The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase., Krapp S, Munster-Kuhnel AK, Kaiser JT, Huber R, Tiralongo J, Gerardy-Schahn R, Jacob U, J Mol Biol. 2003 Dec 5;334(4):625-37. PMID:14636592

Page seeded by OCA on Sun Mar 30 23:19:56 2008