1g97
From Proteopedia
| |||||||
| , resolution 1.96Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , | ||||||
| Activity: | UDP-N-acetylglucosamine diphosphorylase, with EC number 2.7.7.23 | ||||||
| Related: | 1G95
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
S.PNEUMONIAE GLMU COMPLEXED WITH UDP-N-ACETYLGLUCOSAMINE AND MG2+
Overview
N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) is an essential bacterial enzyme with both an acetyltransferase and a uridyltransferase activity which have been mapped to the C-terminal and N-terminal domains, respectively. GlmU performs the last two steps in the synthesis of UDP-N-acetylglucosamine (UDP-GlcNAc), which is an essential precursor in both the peptidoglycan and the lipopolysaccharide metabolic pathways. GlmU is therefore an attractive target for potential antibiotics. Knowledge of its three-dimensional structure would provide a basis for rational drug design. We have determined the crystal structures of Streptococcus pneumoniae GlmU (SpGlmU) in apo form at 2.33 A resolution, and in complex with UDP-N-acetyl glucosamine and the essential co-factor Mg(2+) at 1.96 A resolution. The protein structure consists of an N-terminal domain with an alpha/beta-fold, containing the uridyltransferase active site, and a C-terminal domain with a long left-handed beta-sheet helix (LbetaH) domain. An insertion loop containing the highly conserved sequence motif Asn-Tyr-Asp-Gly protrudes from the left-handed beta-sheet helix domain. In the crystal, S. pneumoniae GlmU forms exact trimers, mainly through contacts between left-handed beta-sheet helix domains. UDP-N-acetylglucosamine and Mg(2+) are bound at the uridyltransferase active site, which is in a closed form. We propose a uridyltransferase mechanism in which the activation energy of the double negatively charged phosphorane transition state is lowered by charge compensation of Mg(2+) and the side-chain of Lys22.
About this Structure
1G97 is a Single protein structure of sequence from Streptococcus pneumoniae. Full crystallographic information is available from OCA.
Reference
Crystal structures of Streptococcus pneumoniae N-acetylglucosamine-1-phosphate uridyltransferase, GlmU, in apo form at 2.33 A resolution and in complex with UDP-N-acetylglucosamine and Mg(2+) at 1.96 A resolution., Kostrewa D, D'Arcy A, Takacs B, Kamber M, J Mol Biol. 2001 Jan 12;305(2):279-89. PMID:11124906
Page seeded by OCA on Sun Mar 30 20:39:18 2008
