Olsén A, Jonsson A, Normark S
Department of Microbiology, University of Umeå, Sweden.
Nature. 1989 Apr 20;338(6217):652-5. doi: 10.1038/338652a0.
Gram-negative bacteria are known to produce two types of surface organelles: flagella, which are required for motility and chemotaxis, and pili (fimbriae), which play a part in the interaction of bacteria with other bacteria and with eukaryotic host cells. Here we report a third class of E. coli surface organelles for which we propose the name curli. Curli are coiled surface structures composed of a single type of subunit, the curlin, which differs from all known pilin proteins and is synthesized in the absence of a cleavable signal peptide. Although the gene encoding this structural subunit, crl, is present and transcribed in most natural isolates of E. coli, only certain strains are able to assemble the subunit protein into curli. This assembly process occurs preferentially at growth temperatures below 37 degrees C. The ability of curli to mediate binding to fibronectin may be a virulence-associated property for wound colonization and for the colonization of fibronectin-coated surfaces.
鞭毛，它是运动性和趋化性所必需的；菌毛（纤毛），它在细菌与其他细菌以及与真核宿主细胞的相互作用中发挥作用。在此，我们报告了大肠杆菌的第三类表面细胞器，我们将其命名为卷曲菌毛。卷曲菌毛是由单一类型的亚基卷曲菌素组成的螺旋状表面结构，该亚基不同于所有已知的菌毛蛋白，且在没有可裂解信号肽的情况下合成。尽管编码这种结构亚基的基因crl在大多数大肠杆菌自然分离株中都存在并转录，但只有某些菌株能够将亚基蛋白组装成卷曲菌毛。这种组装过程优先在低于37摄氏度的生长温度下发生。卷曲菌毛介导与纤连蛋白结合的能力可能是与伤口定植以及在纤连蛋白包被表面定植相关的毒力特性。
