Molecular characterization of inulosucrase from Leuconostoc citreum: a fructosyltransferase within a glucosyltransferase.

ABSTRACT: The gene coding for inulosucrase in Leuconostoc citreum CW28, islA, was cloned, sequenced, and expressed in Escherichia coli. The recombinant enzyme catalyzed inulin synthesis from sucrose like the wild-type enzyme. Inulosucrase presents an unusual structure: its N-terminal region is similar to the variable region of glucosyltransferases, its catalytic domain is similar to fructosyltransferases from various microorganisms, and its C-terminal domain presents similarity to the glucan binding domain from alternansucrase, a glucosyltransferase from Leuconostoc mesenteroides NRRL B-1355. From sequence comparison, it was found that this fructosyltransferase is a natural chimeric enzyme resulting from the substitution of the catalytic domain of alternansucrase by a fructosyltransferase. Two diffe

SUBMITTER: Olivares-Illana V 

PROVIDER: S-EPMC156214 | biostudies-literature | 2003 Jun

REPOSITORIES: biostudies-literature