Structural insights into a novel Ca2+-independent PL-6 alginate lyase from Vibrio OU02 identify the possible subsites responsible for product distribution

In this study, we characterized a novel single-domain PL-6 alginate lyase (named AlyF). According to the biochemical analysis, AlyF possesses unique features compared with other PL-6 enzymes, including (1) a Ca2+-independent catalytic mechanism and (2) a PolyG-specific cleavage specificity that predominantly produces trisaccharides. The structures of AlyF and its complexes described here reveal the structural basis for these unique features and substrate binding mechanisms, which were further confirmed using mutagenesis. More importantly, we determined the possible subsites specifying the predominantly trisaccharide products of AlyF, which may facilitate the rational design of AlyF for potential applications in preparing a single alginate oligomer.

Source: Biochimica et Biophysica Acta (BBA) General Subjects - April 19, 2019 Category: Biochemistry Source Type: research