Identification of discrete domains within gonococcal transferrin-binding protein A that are necessary for ligand binding and iron uptake functions.

ABSTRACT: The availability of free iron in vivo is strictly limited, in part by the iron-binding protein transferrin. The pathogenic Neisseria spp. can sequester iron from this protein, dependent upon two iron-repressible, transferrin-binding proteins (TbpA and TbpB). TbpA is a TonB-dependent, integral, outer membrane protein that may form a beta-barrel exposing multiple surface loops, some of which are likely to contain ligand-binding motifs. In this study we propose a topological model of gonococcal TbpA and then test some of the hypotheses set forth by the model by individually deleting three putative loops (designated loops 4, 5, and 8). Each mutant TbpA could be expressed without toxicity and was surface exposed as assessed by immunoblotting, transferrin binding, and protease accessibility. Del

SUBMITTER: Boulton IC 

PROVIDER: S-EPMC97808 | biostudies-literature | 2000 Dec

REPOSITORIES: biostudies-literature