Abstract

The results of studies on mce operons of the causative agent Mycobacterium tuberculosis and actinobacteria are summarized. Mce transporters belong to a group of cell-wall proteins. The genome of M. tuberculosis contains four mce operons that encode complexes, each of which consists of two integral membrane proteins (YrbEB) followed by six other Mce proteins (MceA–F). These proteins are functionally similar to ABC transporters. Despite their significant role in the pathogenesis of M. tuberculosis infection, Mce proteins remain poorly studied due to their complex structure and operon regulation. However, a number of their functions have been characterized; they include the penetration of host cells by M. tuberculosis and its survival, as well as the transport of cholesterol and mycolic acids, which are pathogenicity factors of no small importance. The expression of mce operons depends on many factors, such as the growth phase, the culture medium, and the localization of M. tuberculosis infection. Today, strains of M. tuberculosis and M. bovis with deleted mce operons are considered candidates for the development of new attenuated vaccines that might one day replace the M. bovis BCG vaccine, which is no longer deemed strong enough to hold back the tuberculosis epidemic.

中文翻译：

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放线菌mce操纵子：结构和功能。

摘要

总结了致病菌结核分枝杆菌和放线菌对mce操纵子的研究结果。Mce转运蛋白属于一组细胞壁蛋白。结核分枝杆菌的基因组包含四个编码复合物的mce操纵子，每个操纵子由两个完整的膜蛋白（YrbEB）和随后的六个其他Mce蛋白（MceA–F）组成。这些蛋白质在功能上类似于ABC转运蛋白。尽管它们在结核分枝杆菌的发病机理中具有重要作用 感染后，由于其复杂的结构和操纵子调控，Mce蛋白的研究仍然很少。但是，已经表征了它们的许多功能。它们包括结核分枝杆菌对宿主细胞的渗透及其存活，以及胆固醇和霉菌酸的运输，这是不小的重要性的致病因素。mce操纵子的表达取决于许多因素，例如生长期，培养基和结核分枝杆菌感染的定位。如今，已删除了mce操纵子的结核分枝杆菌和牛分枝杆菌菌株被认为是开发新的减毒疫苗的候选药物，这种疫苗可能有一天会取代牛分枝杆菌卡介苗，这种疫苗不再被认为足以抵抗结核病的流行。