3OM6

Crystal structure of B. megaterium levansucrase mutant Y247A

Summary for 3OM6

• Entry DOI: 10.2210/pdb3om6/pdb
• Related: 3OM2 3OM4 3OM5 3OM7
• Descriptor: Levansucrase, CALCIUM ION, SULFATE ION, ... (5 entities in total)
• Functional Keywords: five fold beta-propeller, levansucrase, transferase
• Biological source: Bacillus megaterium (Bacillus fructosus)
• Total number of polymer chains: 4
• Total formula weight: 204714.04

Authors

Strube, C.P.,Homann, A.,Gamer, M.,Jahn, D.,Seibel, J.,Heinz, D.W. (deposition date: 2010-08-26, release date: 2011-03-23, Last modification date: 2024-02-21)

Primary citation

Strube, C.P.,Homann, A.,Gamer, M.,Jahn, D.,Seibel, J.,Heinz, D.W.
Polysaccharide Synthesis of the Levansucrase SacB from Bacillus megaterium Is Controlled by Distinct Surface Motifs.
J.Biol.Chem., 286:17593-17600, 2011

PubMed Abstract: Despite the widespread biological function of carbohydrates, the polysaccharide synthesis mechanisms of glycosyltransferases remain largely unexplored. Bacterial levansucrases (glycoside hydrolase family 68) synthesize high molecular weight, β-(2,6)-linked levan from sucrose by transfer of fructosyl units. The kinetic and biochemical characterization of Bacillus megaterium levansucrase SacB variants Y247A, Y247W, N252A, D257A, and K373A reveal novel surface motifs remote from the sucrose binding site with distinct influence on the polysaccharide product spectrum. The wild type activity (k(cat)) and substrate affinity (K(m)) are maintained. The structures of the SacB variants reveal clearly distinguishable subsites for polysaccharide synthesis as well as an intact active site architecture. These results lead to a new understanding of polysaccharide synthesis mechanisms. The identified surface motifs are discussed in the context of related glycosyltransferases.

PubMed: 21454585
DOI: 10.1074/jbc.M110.203166

Experimental method

X-RAY DIFFRACTION (1.96 Å)