Kirby S D, Gray-Owen S D, Schryvers A B
Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada.
Mol Microbiol. 1997 Sep;25(5):979-87. doi: 10.1111/j.1365-2958.1997.mmi535.x.
Ferric-binding proteins (FbpA) have been implicated in the transferrin receptor-mediated iron acquisition pathways of Haemophilus influenzae and Neisseria spp. These proteins are believed to function by shuttling iron from outer membrane transferrin receptors to a specific inner membrane permease complex. However, the role of these proteins has not been conclusively resolved, as attempts at creating isogenic mutants in the fbpA genes of both species have been unsuccessful, prompting the hypothesis that FbpA may play a critical role in H. influenzae and Neisseria spp. This study describes the construction and characterization of an H. influenzae isogenic fbpA mutant. It is demonstrated that this mutant is deficient in its ability to use human transferrin as a sole iron source, even though the strain is still competent for binding human transferrin. It is also demonstrated that this mutant is impaired in its ability to use ferric citrate as an iron source, and grows at a reduced rate relative to wild type in broth supplemented with protoporphyrin rather than haemin.
铁结合蛋白（FbpA）与流感嗜血杆菌和奈瑟菌属中运铁蛋白受体介导的铁获取途径有关。这些蛋白被认为通过将铁从外膜运铁蛋白受体转运到特定的内膜通透酶复合物来发挥作用。然而，这些蛋白的作用尚未最终确定，因为在这两个物种的fbpA基因中创建同基因突变体的尝试均未成功，这促使人们提出假说，即FbpA可能在流感嗜血杆菌和奈瑟菌属中起关键作用。本研究描述了流感嗜血杆菌同基因fbpA突变体的构建和特性。结果表明，该突变体在将人运铁蛋白作为唯一铁源使用的能力上存在缺陷，尽管该菌株仍然能够结合人运铁蛋白。还表明该突变体在使用柠檬酸铁作为铁源的能力上受损，并且在补充原卟啉而非血红素的肉汤中相对于野生型生长速率降低。
