Structural Basis for the Interconversion of Maltodextrins by MalQ, the Amylomaltase of Escherichia coli.

ABSTRACT: Amylomaltase MalQ is essential for the metabolism of maltose and maltodextrins in Escherichia coli. It catalyzes transglycosylation/disproportionation reactions in which glycosyl or dextrinyl units are transferred among linear maltodextrins of various lengths. To elucidate the molecular basis of transglycosylation by MalQ, we have determined three crystal structures of this enzyme, i.e. the apo-form, its complex with maltose, and an inhibitor complex with the transition state analog acarviosine-glucose-acarbose, at resolutions down to 2.1 Å. MalQ represents the first example of a mesophilic bacterial amylomaltase with known structure and exhibits an N-terminal extension of about 140 residues, in contrast with previously described thermophilic enzymes. This moiety seems unique to amylomalta

SUBMITTER: Weiss SC 

PROVIDER: S-EPMC4571864 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature