1QWJ

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

Summary for 1QWJ

• Entry DOI: 10.2210/pdb1qwj/pdb
• Related: 1EYR 1GQC
• Descriptor: cytidine monophospho-N-acetylneuraminic acid synthetase, CYTIDINE-5'-MONOPHOSPHATE-5-N-ACETYLNEURAMINIC ACID (3 entities in total)
• Functional Keywords: cmp-5-n-acetylneuraminic acid synthetase, cmp-neu5ac, sialic acid, glycosylation, lipopolysaccharide biosynthesis, sugar-activating enzyme, transferase
• Biological source: Mus musculus (house mouse)
• Cellular location: Nucleus: Q99KK2
• Total number of polymer chains: 4
• Total formula weight: 106193.17

Authors

Krapp, S.,Muenster-Kuehnel, A.K.,Kaiser, J.T.,Huber, R.,Tiralongo, J.,Gerardy-Schahn, R.,Jacob, U. (deposition date: 2003-09-02, release date: 2003-12-09, Last modification date: 2024-04-03)

Primary citation

Krapp, S.,Muenster-Kuehnel, A.K.,Kaiser, J.T.,Huber, R.,Tiralongo, J.,Gerardy-Schahn, R.,Jacob, U.
The Crystal Structure of Murine CMP-5-N-acetylneuraminic Acid Synthetase
J.Mol.Biol., 334:625-637, 2003

PubMed Abstract: 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.

PubMed: 14636592
DOI: 10.1016/j.jmb.2003.09.080

Experimental method

X-RAY DIFFRACTION (2.8 Å)