Saier M H, Tam R, Reizer A, Reizer J
Department of Biology, University of California at San Diego, La Jolla 92093-0116.
Mol Microbiol. 1994 Mar;11(5):841-7. doi: 10.1111/j.1365-2958.1994.tb00362.x.
Homology has been established for members of two families of functionally related bacterial membrane proteins. The first family (the resistance/nodulation/cell division (RND) family) includes (i) two metal-resistance efflux pumps in Alcaligenes eutrophus (CzcA and CnrA), (ii) three proteins which function together in nodulation of alfalfa roots by Rhizobium meliloti (NoIGHI), and (iii) a cell division protein in Escherichia coli (EnvD). The second family (the putative membrane fusion protein (MFP) family) includes a nodulation protein (NoIF), a cell division protein (EnvC), and a multidrug resistance transport protein (EmrA). We propose that an MFP functions co-operatively with an RND protein to transport large or hydrophobic molecules across the two membranes of the Gram-negative bacterial cell envelope.
已确定功能相关的两类细菌膜蛋白家族成员之间存在同源性。第一个家族（抗性/结瘤/细胞分裂（RND）家族）包括：（i）嗜碱假单胞菌中的两种金属抗性外排泵（CzcA和CnrA）；（ii）在苜蓿中华根瘤菌结瘤过程中共同发挥作用的三种蛋白质（NoIGHI）；（iii）大肠杆菌中的一种细胞分裂蛋白（EnvD）。第二个家族（假定的膜融合蛋白（MFP）家族）包括一种结瘤蛋白（NoIF）、一种细胞分裂蛋白（EnvC）和一种多药抗性转运蛋白（EmrA）。我们提出，一种MFP与一种RND蛋白协同发挥作用，以将大分子或疏水分子转运穿过革兰氏阴性细菌细胞包膜的两层膜。
