2X63

Crystal structure of the sialyltransferase CST-II N51A in complex with CMP

Summary for 2X63

• Entry DOI: 10.2210/pdb2x63/pdb
• Related: 1RO7 1RO8 2X61 2X62
• Descriptor: ALPHA-2,3-/2,8-SIALYLTRANSFERASE, 1,2-ETHANEDIOL, CYTIDINE-5'-MONOPHOSPHATE, ... (4 entities in total)
• Functional Keywords: glycosyltransferase, gta, transferase
• Biological source: CAMPYLOBACTER JEJUNI
• Total number of polymer chains: 1
• Total formula weight: 30728.68

Authors

Lee, H.J.,Lairson, L.L.,Rich, J.R.,Wakarchuk, W.W.,Withers, S.G.,Strynadka, N.C.J. (deposition date: 2010-02-14, release date: 2011-02-23, Last modification date: 2025-12-17)

Primary citation

Lee, H.J.,Lairson, L.L.,Rich, J.R.,Lameignere, E.,Wakarchuk, W.W.,Withers, S.G.,Strynadka, N.C.J.
Structural and Kinetic Analysis of Substrate Binding to the Sialyltransferase Cst-II from Campylobacter Jejuni.
J.Biol.Chem., 286:35922-, 2011

PubMed Abstract: Sialic acids play important roles in various biological processes and typically terminate the oligosaccharide chains on the cell surfaces of a wide range of organisms, including mammals and bacteria. Their attachment is catalyzed by a set of sialyltransferases with defined specificities both for their acceptor sugars and the position of attachment. However, little is known of how this specificity is encoded. The structure of the bifunctional sialyltransferase Cst-II of the human pathogen Campylobacter jejuni in complex with CMP and the terminal trisaccharide of its natural acceptor (Neu5Ac-α-2,3-Gal-β-1,3-GalNAc) has been solved at 1.95 Å resolution, and its kinetic mechanism was shown to be iso-ordered Bi Bi, consistent with its dual acceptor substrate specificity. The trisaccharide acceptor is seen to bind to the active site of Cst-II through interactions primarily mediated by Asn-51, Tyr-81, and Arg-129. Kinetic and structural analyses of mutants modified at these positions indicate that these residues are critical for acceptor binding and catalysis, thereby providing significant new insight into the kinetic and catalytic mechanism, and acceptor specificity of this pathogen-encoded bifunctional GT-42 sialyltransferase.

PubMed: 21832050
DOI: 10.1074/JBC.M111.261172

Experimental method

X-RAY DIFFRACTION (2 Å)