%0 Journal Article %A Ferrando, Maria Laura %A Fuentes, Susana %A de Greeff, Astrid %A Smith, Hilde %A Wells, Jerry M. %T ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus %D 2010 %J Microbiology, %V 156 %N 9 %P 2818-2828 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.037960-0 %K Spc, spectinomycin %K Erm, erythromycin %K GAS, group A streptococci %K GBS, group B streptococci %I Microbiology Society, %X 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. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.037960-0