Crystal structure of levansucrase from the Gram-negative bacterium Gluconacetobacter diazotrophicus.

ABSTRACT: The endophytic Gram-negative bacterium Gluconacetobacter diazotrophicus SRT4 secretes a constitutively expressed levansucrase (LsdA, EC 2.4.1.10), which converts sucrose into fructooligosaccharides and levan. The enzyme is included in GH (glycoside hydrolase) family 68 of the sequence-based classification of glycosidases. The three-dimensional structure of LsdA has been determined by X-ray crystallography at a resolution of 2.5 A (1 A=0.1 nm). The structure was solved by molecular replacement using the homologous Bacillus subtilis (Bs) levansucrase (Protein Data Bank accession code 1OYG) as a search model. LsdA displays a five-bladed beta-propeller architecture, where the catalytic residues that are responsible for sucrose hydrolysis are perfectly superimposable with the equivalent residue

SUBMITTER: Martinez-Fleites C 

PROVIDER: S-EPMC1188265 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature