Joh D, Wann E R, Kreikemeyer B, Speziale P, Höök M
Center for Extracellular Matrix Biology, Albert B. Alkek Institute of Biosciences and Technology, Texas A&M University System, Houston 77030, USA.
Matrix Biol. 1999 Jun;18(3):211-23. doi: 10.1016/s0945-053x(99)00025-6.
Most bacterial infections are initiated by the adherence of microorganisms to host tissues. This process involves the interaction of specific bacterial surface structures, called adhesins, with host components. In this review, we discuss a group of microbial adhesins known as Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs) which recognize and bind FN. The interaction of bacteria with FN is believed to contribute significantly to the virulence of a number of microorganisms, including staphylococci and streptococci. Several FN-binding MSCRAMMs of staphylococci and streptococci exhibit a similar structural organization and mechanism of ligand recognition. The ligand-binding domain consists of tandem repeats of a approximately 45 amino acid long unit which bind to the 29-kDa N-terminal region of FN. The binding mechanism is unusual in that the repeat units are unstructured and appear to undergo a conformational change upon ligand binding. Apart from supporting bacterial adherence, FN is also involved in bacterial entry into non-phagocytic mammalian cells. A sandwich model has been proposed in which FN forms a molecular bridge between MSCRAMMs on the bacterial surface and integrins on the host cell. However, the precise mechanism of bacterial invasion and the roles of FN and integrins in this process have yet to be fully elucidated.
大多数细菌感染是由微生物黏附于宿主组织引发的。这一过程涉及特定的细菌表面结构（称为黏附素）与宿主成分之间的相互作用。在本综述中，我们讨论了一类被称为识别黏附基质分子的微生物表面成分（MSCRAMMs）的微生物黏附素，它们能识别并结合纤连蛋白（FN）。细菌与FN的相互作用被认为对包括葡萄球菌和链球菌在内的多种微生物的毒力有显著贡献。葡萄球菌和链球菌的几种FN结合型MSCRAMMs表现出相似的结构组织和配体识别机制。配体结合结构域由大约45个氨基酸长的单元串联重复组成，这些单元与FN的29 kDa N端区域结合。结合机制不同寻常之处在于重复单元是无结构的，并且在配体结合时似乎会发生构象变化。除了支持细菌黏附外，FN还参与细菌进入非吞噬性哺乳动物细胞的过程。有人提出了一种三明治模型，其中FN在细菌表面的MSCRAMMs和宿主细胞上的整合素之间形成分子桥。然而，细菌入侵的确切机制以及FN和整合素在此过程中的作用尚未完全阐明。
