ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus
ApuA, a multifunctional α-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus
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DOI：
10.1099/mic.0.037960-0
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发表时间：
2010-09-01
期刊：
影响因子：
2.8
通讯作者：
Wells, Jerry M.
中科院分区：
文献类型：
--
作者：
Ferrando, Maria Laura;Fuentes, Susana;Wells, Jerry M.
我们已经确定了apuA在猪链球菌，它编码一个双功能淀粉普鲁兰酶与保守的α-淀粉酶和普鲁兰酶底物结合结构域和催化基序。ApuA表现出典型的革兰氏阳性表面蛋白的特性，具有推定的信号序列和LPKTGE细胞壁锚定基序。含有ApuA的预测N-末端α-淀粉酶结构域的重组蛋白显示具有α-（1，4）糖苷活性。此外，还发现了一株S. suis缺乏在野生型S的细胞表面蛋白提取物中检测到的普鲁兰酶α-（1，6）糖苷活性。猪。ApuA是在含有支链淀粉作为主要碳源的复杂培养基中正常生长所必需的，这表明该酶通过降解鼻咽和口腔中的糖原和食物来源的淀粉在体内营养获取中起作用。ApuA在体外显示出促进对猪上皮和粘液的粘附，突出了碳水化合物利用与S. suis to colonizing定殖and infect感染the host宿主.
We have identified apuA in Streptococcus suis, which encodes a bifunctional amylopullulanase with conserved alpha-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 alpha-amylase domain of ApuA was shown to have alpha-(1,4) glycosidic activity. Additionally, an apuA mutant of S. suis lacked the pullulanase alpha-(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.