2bkv
STRUCTURE AND KINETICS OF A MONOMERIC GLUCOSAMINE-6-PHOSPHATE DEAMINASE: MISSING LINK OF THE NAGB SUPERFAMILY
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OverviewOverview
Glucosamine 6-phosphate is converted to fructose 6-phosphate and ammonia, by the action of the enzyme glucosamine 6-phosphate deaminase, NagB. This, reaction is the final step in the specific GlcNAc utilization pathway and, thus decides the metabolic fate of GlcNAc. Sequence analyses suggest that, the NagB "superfamily" consists of three main clusters: multimeric and, allosterically regulated glucosamine-6-phosphate deaminases (exemplified, by Escherichia coli NagB), phosphogluconolactonases, and monomeric, hexosamine-6-phosphate deaminases. Here we present the three-dimensional, structure and kinetics of the first member of this latter group, the, glucosamine-6-phosphate deaminase, NagB, from Bacillus subtilis. The, structures were determined in ligand-complexed forms at resolutions around, 1.4 Angstroms. BsuNagB is monomeric in solution and as a consequence is, active (k(cat) 28 s(-1), K(m(app)) 0.13 mM) without the need for, allosteric activators. A decrease in activity at high substrate, concentrations may reflect substrate inhibition (with K(i) of, approximately 4 mM). The structure completes the NagB superfamily, structural landscape and thus allows further interrogation of genomic data, in terms of the regulation of NagB and the metabolic fate(s) of, glucosamine 6-phosphate.
About this StructureAbout this Structure
2BKV is a Single protein structure of sequence from Bacillus subtilis with PGA as ligand. Active as Glucosamine-6-phosphate deaminase, with EC number 3.5.99.6 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Structure and kinetics of a monomeric glucosamine 6-phosphate deaminase: missing link of the NagB superfamily?, Vincent F, Davies GJ, Brannigan JA, J Biol Chem. 2005 May 20;280(20):19649-55. Epub 2005 Mar 8. PMID:15755726
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