@article{mbs:/content/journal/micro/10.1099/mic.0.037960-0, author = "Ferrando, Maria Laura and Fuentes, Susana and de Greeff, Astrid and Smith, Hilde and Wells, Jerry M.", title = "ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus", journal= "Microbiology", year = "2010", volume = "156", number = "9", pages = "2818-2828", doi = "https://doi.org/10.1099/mic.0.037960-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.037960-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "Spc, spectinomycin", keywords = "Erm, erythromycin", keywords = "GAS, group A streptococci", keywords = "GBS, group B streptococci", abstract = "We have identified apuA in Streptococcus suis, which encodes a bifunctional amylopullulanase with conserved α-amylase and pullulanase substrate-binding domains and catalytic motifs. ApuA exhibited properties typical of a Gram-positive surface protein, with a putative signal sequence and LPKTGE cell-wall-anchoring motif. A recombinant protein containing the predicted N-terminal α-amylase domain of ApuA was shown to have α-(1,4) glycosidic activity. Additionally, an apuA mutant of S. suis lacked the pullulanase α-(1,6) glycosidic activity detected in a cell-surface protein extract of wild-type S. suis. ApuA was required for normal growth in complex medium containing pullulan as the major carbon source, suggesting that this enzyme plays a role in nutrient acquisition in vivo via the degradation of glycogen and food-derived starch in the nasopharyngeal and oral cavities. ApuA was shown to promote adhesion to porcine epithelium and mucus in vitro, highlighting a link between carbohydrate utilization and the ability of S. suis to colonize and infect the host.", }