1g97
S.PNEUMONIAE GLMU COMPLEXED WITH UDP-N-ACETYLGLUCOSAMINE AND MG2+
Structural highlights
FunctionGLMU_STRPN Catalyzes the last two sequential reactions in the de novo biosynthetic pathway for UDP-N-acetylglucosamine (UDP-GlcNAc). The C-terminal domain catalyzes the transfer of acetyl group from acetyl coenzyme A to glucosamine-1-phosphate (GlcN-1-P) to produce N-acetylglucosamine-1-phosphate (GlcNAc-1-P), which is converted into UDP-GlcNAc by the transfer of uridine 5-monophosphate (from uridine 5-triphosphate), a reaction catalyzed by the N-terminal domain (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedN-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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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