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 variou ...
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 [2]. This domain called N2 resembles a beta-sandwich consisting of a five-stranded mixed beta-sheet and a short two-stranded antiparallel beta-sheet. The N2 structure is reminiscent of carbohydrate-binding modules (CBMs) [2]. However, a comparison with structurally known CBMs did not reveal significant similarities.
These enzymes EC:2.4.1.25 transfer a segment of a (1,4)-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or (1,4)-alpha-D-glucan [1].