Characterization of Escherichia coli OtsA, a trehalose-6-phosphate synthase from glycosyltransferase family 20

R P Gibson, R M Lloyd, S J Charnock, G J Davies

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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 similar or equal to 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 Angstrom. Data for this form have been collected to 3.0 Angstrom resolution at the CLRC Daresbury Synchrotron Radiation Source. The second form has unit-cell parameters a = b = 141.9, c = 317.8 Angstrom and displays the apparent space group P4(2). These crystals diffract beyond 2 Angstrom resolution, but display merohedral twinning.

Original languageEnglish
Pages (from-to)349-351
Number of pages3
JournalActa Crystallographica. Section D, Biological Crystallography
Publication statusPublished - Feb 2002



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