Premium
Three‐dimensional structures and functional studies of two GH 43 arabinofuranosidases from Weissella sp. strain 142 and Lactobacillus brevis
Author(s) -
LinaresPastén Javier A.,
Falck Peter,
Albasri Khalil,
Kjellström Sven,
Adlercreutz Patrick,
Logan Derek T.,
Karlsson Eva Nordberg
Publication year - 2017
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14101
Subject(s) - strain (injury) , weissella , microbiology and biotechnology , lactobacillus brevis , lactobacillus , biology , food science , chemistry , bacteria , genetics , anatomy , lactic acid , lactobacillus plantarum , leuconostoc
Arabinofuranosidases degrade arabinose‐containing oligo and polysaccharides, releasing l ‐arabinose, which is a potentially useful sugar, shown to reduce glycemic response under certain conditions. Arabinofuranosidases (Arafs) are frequently found in GH 43, one of the most common GH ‐families encoded in genomes in gut microbiota, and hence it is of interest to increase understanding of the function of these enzymes in species occurring in the gut. Here we have produced, characterized and solved the three‐dimensional structures, at 1.9 and 2.0 Å resolution respectively, of two homologous GH 43 enzymes, classified under subfamily 26, from Lactobacillus brevis DSM 1269 ( Lb Araf43) and Weissella strain 142 ( W A raf43), respectively. The enzymes, with 74% sequence identity to each other, are composed of a single catalytic module with a β‐propeller structure typical of GH 43, and an active‐site pocket with three identifiable subsites (−1, +1, and +2). According to size exclusion chromatography, native W A raf43 is a dimer, while Lb Araf43 is a tetramer in solution. Both of them show activity with similar catalytic efficiency on 1,5‐α‐ l ‐arabinooligosaccharides with a degree of polymerization ( DP ) of 2–3. Activity is restricted to substrates of low DP , and the reason for this is believed to be an extended loop at the entrance to the active site, creating interactions in the +2 subsite. Database Structural data are available in the PDB under the accession numbers 5M8B ( Lb Araf43) and 5M8E ( W A raf43).