title: Characterization of Escherichia coli OtsA, a trehalose-6-phosphate synthase from glycosyltransferase family 20.
abstract: The Ots gene cluster of Escherichia coli encodes the synthetic apparatus for the formation of alpha,alpha-1,1-trehalose, a non-reducing glucose disaccharide. The otsA gene encodes a trehalose-6-phosphate synthase, a glycosyltransferase which catalyses the synthesis of alpha,alpha-1,1-trehalose-6-phosphate from glucose-6-phosphate using a UDP-glucose donor. It has been classified into glycosyltransferase family GT-20 based upon amino-acid sequence similarities. The otsA gene has been cloned and recombinant protein overexpressed using a pET-based system in E. coli BL21 cells. The recombinant protein (MW approximately 54.7 kDa) is active and has been crystallized in two forms suitable for X-ray diffraction analysis. The first is orthorhombic, P2(1)2(1)2(1), with unit-cell parameters a = 104.1, b = 127.8, c = 179.9 A. Data for this form have been collected to 3.0 A resolution at the CLRC Daresbury Synchrotron Radiation Source. The second form has unit-cell parameters a = b = 141.9, c = 317.8 A and displays the apparent space group P4(2). These crystals diffract beyond 2 A resolution, but display merohedral twinning.
authors.affiliation: Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, England.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Gibson
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Lloyd
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Charnock
authors.forename: Gideon J
authors.initials: GJ
authors.lastname: Davies
mesh_terms: D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D005964:Glucosyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016695:Glycosyltransferases / Q000145:classification; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D016695:Glycosyltransferases; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase