Biswas G D, Sparling P F
Department of Medicine, University of North Carolina, Chapel Hill 27599, USA.
Infect Immun. 1995 Aug;63(8):2958-67. doi: 10.1128/iai.63.8.2958-2967.1995.
Neisseria gonorrhoeae acquires iron (Fe) efficiently from lactoferrin (LF). A 103-kDa gonococcal outer membrane LF-binding protein (Lbp) was identified previously. We isolated the structural gene lbpA for Lbp1 by screening a gonococcal library for a clone that could repair an LF- receptor mutant. An mTnCm3 transposon insertion mutant of lbpA was unable to use LF-bound Fe for growth, unable to bind LF to whole cells, and unable to express Lbp1. The DNA sequence of lbpA predicted a protein that shared 94% identity with the meningococcal LF receptor protein, Lbp, and was closely related to Tbp1, one of the transferrin receptor proteins. Clinical isolates of gonococci are frequently unable to acquire Fe from LF, and LF- isolates do not have a functional LF receptor. The wild-type lbpA gene transformed most tested LF- clinical isolates to LF+, indicating that lbpA is defective in many clinical isolates.
淋病奈瑟菌能有效地从乳铁蛋白（LF）中获取铁（Fe）。先前已鉴定出一种103 kDa的淋球菌外膜LF结合蛋白（Lbp）。我们通过筛选淋球菌文库以寻找能够修复LF受体突变体的克隆，从而分离出Lbp1的结构基因lbpA。lbpA的mTnCm3转座子插入突变体无法利用与LF结合的铁进行生长，无法将LF结合到全细胞上，也无法表达Lbp1。lbpA的DNA序列预测的一种蛋白质与脑膜炎球菌LF受体蛋白Lbp有94%的同一性，并且与转铁蛋白受体蛋白之一的Tbp1密切相关。淋病奈瑟菌的临床分离株常常无法从LF中获取铁，且LF阴性分离株没有功能性的LF受体。野生型lbpA基因将大多数测试的LF阴性临床分离株转化为LF阳性，这表明lbpA在许多临床分离株中存在缺陷。
