An 1,4-α-Glucosyltransferase Defines a New Maltodextrin Catabolism Scheme in Lactobacillus acidophilus.

ABSTRACT: The maltooligosaccharide (MOS) utilization locus in Lactobacillus acidophilus NCFM, a model for human small-intestine lactobacilli, encodes three glycoside hydrolases (GHs): a putative maltogenic α-amylase of family 13, subfamily 20 (LaGH13_20), a maltose phosphorylase of GH65 (LaGH65), and a family 13, subfamily 31, member (LaGH13_31B), annotated as a 1,6-α-glucosidase. Here, we reveal that LaGH13_31B is a 1,4-α-glucosyltransferase that disproportionates MOS with a degree of polymerization of ≥2, with a preference for maltotriose. Kinetic analyses of the three GHs encoded by the MOS locus revealed that the substrate preference of LaGH13_31B toward maltotriose complements the ~40-fold lower k_cat of LaGH13_20 toward this sub

SUBMITTER: Andersen S 

PROVIDER: S-EPMC7376546 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature