2XCI

Membrane-embedded monofunctional glycosyltransferase WaaA of Aquifex aeolicus, substrate-free form

Summary for 2XCI

• Entry DOI: 10.2210/pdb2xci/pdb
• Related: 2XCU
• Descriptor: 3-DEOXY-D-MANNO-2-OCTULOSONIC ACID TRANSFERASE, TETRAETHYLENE GLYCOL, GLYCEROL, ... (7 entities in total)
• Functional Keywords: transferase, kdta, gsea, glycosyltransferase superfamily b, gt-b
• Biological source: AQUIFEX AEOLICUS
• Total number of polymer chains: 4
• Total formula weight: 175303.46

Authors

Schmidt, H.,Hansen, G.,Hilgenfeld, R.,Mamat, U.,Mesters, J.R. (deposition date: 2010-04-26, release date: 2011-05-11, Last modification date: 2019-05-15)

Primary citation

Schmidt, H.,Hansen, G.,Singh, S.,Hanuszkiewicz, A.,Lindner, B.,Fukase, K.,Woodard, R.W.,Holst, O.,Hilgenfeld, R.,Mamat, U.,Mesters, J.R.
Structural and Mechanistic Analysis of the Membrane-Embedded Glycosyltransferase Waaa Required for Lipopolysaccharide Synthesis.
Proc.Natl.Acad.Sci.USA, 109:6253-, 2012

PubMed Abstract: WaaA is a key enzyme in the biosynthesis of LPS, a critical component of the outer envelope of Gram-negative bacteria. Embedded in the cytoplasmic face of the inner membrane, WaaA catalyzes the transfer of 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) to the lipid A precursor of LPS. Here we present crystal structures of the free and CMP-bound forms of WaaA from Aquifex aeolicus, an ancient Gram-negative hyperthermophile. These structures reveal details of the CMP-binding site and implicate a unique sequence motif (GGS/TX(5)GXNXLE) in Kdo binding. In addition, a cluster of highly conserved amino acid residues was identified which represents the potential membrane-attachment and acceptor-substrate binding site of WaaA. A series of site-directed mutagenesis experiments revealed critical roles for glycine 30 and glutamate 31 in Kdo transfer. Our results provide the structural basis of a critical reaction in LPS biosynthesis and allowed the development of a detailed model of the catalytic mechanism of WaaA.

PubMed: 22474366
DOI: 10.1073/PNAS.1119894109

Experimental method

X-RAY DIFFRACTION (2 Å)