1oyg
From Proteopedia
Crystal structure of Bacillus subtilis levansucrase
Overview
Many bacteria and about 40,000 plant species form primary carbohydrate reserves based on fructan; these polymers of beta-D-fructofuranose are thought to confer tolerance to drought and frost in plants. Microbial fructan, the beta(2,6)-linked levan, is synthesized directly from sucrose by levansucrase, which is able to catalyze both sucrose hydrolysis and levan polymerization. The crystal structure of Bacillus subtilis levansucrase, determined to a resolution of 1.5 A, shows a rare five-fold beta-propeller topology with a deep, negatively charged central pocket. Arg360, a residue essential for polymerase activity, lies in a solvent-exposed site adjacent to the central pocket. Mutagenesis data and the sucrose-bound structure of inactive levansucrase E342A, at a resolution of 2.1 A, strongly suggest that three conserved acidic side chains in the central pocket are critical for catalysis, and presumably function as nucleophile (Asp86) and general acid (Glu342), or stabilize the transition state (Asp247).
About this Structure
1OYG is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structural framework of fructosyl transfer in Bacillus subtilis levansucrase., Meng G, Futterer K, Nat Struct Biol. 2003 Nov;10(11):935-41. Epub 2003 Sep 28. PMID:14517548 Page seeded by OCA on Sat May 3 04:26:01 2008
