Adhesive pili in Gram-positive bacteria represent a variety of extracellular multiprotein polymers that mediate bacterial colonization of specific host tissues and associated pathogenesis. Pili are assembled in two distinct but coupled steps, an orderly crosslinking of pilin monomers and subsequent anchoring of the polymer to peptidoglycan, catalyzed by two transpeptidase enzymes – the pilus-specific sortase and the housekeeping sortase. Here, we review this biphasic assembly mechanism based on studies of two prototypical models, the heterotrimeric pili in Corynebacterium diphtheriae and the heterodimeric pili in Actinomyces oris, highlighting some newly emerged basic paradigms. The disparate mechanisms of protein ligation mediated by the pilus-specific sortase and the spatial positioning of adhesive pili on the cell surface modulated by the housekeeping sortase are among the notable highlights.

革兰氏阳性菌中的粘附菌毛代表多种细胞外多蛋白聚合物，可介导特定宿主组织的细菌定植和相关发病机制。菌毛在两个不同但耦合的步骤中组装，即菌毛蛋白单体的有序交联和随后聚合物与肽聚糖的锚定，由两种转肽酶 - 菌毛特异性分选酶和管家分选酶催化。在这里，我们基于对两个原型模型的研究，即白喉棒状杆菌中的异源三聚体菌毛和口放线菌中的异源二聚体菌毛，回顾了这种双相组装机制。，突出了一些新出现的基本范式。由菌毛特异性分选酶介导的蛋白质连接的不同机制和由管家分选酶调节的粘附菌毛在细胞表面的空间定位是值得注意的亮点。