Sauer F G, Knight S D, Waksman and G J, Hultgren S J
Departments of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Semin Cell Dev Biol. 2000 Feb;11(1):27-34. doi: 10.1006/scdb.1999.0348.
The assembly of adhesive pili from individual subunits by periplasmic PapD-like chaperones in Gram-negative bacteria offers insight into the complex process of organelle biogenesis. PapD-like chaperones bind, stabilize, and cap interactive surfaces of subunits until they are assembled into the pilus. Subunits lack the seventh *gb-strand necessary to complete their immunoglobulin-like folds; the chaperone supplies this missing strand. Indeed, the chaperone may act as a template, providing steric information to facilitate subunit folding. In the mature pilus, each subunit is thought to supply the missing strand to complete the fold of its neighbor. Thus, one general function of chaperones in organelle biogenesis may be to cap highly interactive surfaces of subunits until they reach the proper assembly site.
革兰氏阴性菌中，周质区类PapD分子伴侣将单个亚基组装成黏附菌毛，这为细胞器生物发生的复杂过程提供了见解。类PapD分子伴侣结合、稳定并覆盖亚基的相互作用表面，直至它们组装成菌毛。亚基缺乏完成其免疫球蛋白样折叠所需的第七条β链；分子伴侣提供这条缺失的链。实际上，分子伴侣可能充当模板，提供空间信息以促进亚基折叠。在成熟菌毛中，每个亚基被认为会提供缺失的链以完成其相邻亚基的折叠。因此，分子伴侣在细胞器生物发生中的一个普遍功能可能是覆盖亚基的高度相互作用表面，直至它们到达合适的组装位点。
