Verification of a topology model of PorT as an integral outer-membrane protein in Porphyromonas gingivalis.

ABSTRACT: PorT is a membrane-associated protein shown to be essential for the maturation and secretion of a class of cysteine proteinases, the gingipains, from the periodontal pathogen Porphyromonas gingivalis. It was previously reported that PorT is located on the periplasmic surface of the inner membrane to function as a chaperone for the maturing proteinases. Our modelling suggested it to be an integral outer-membrane protein with eight anti-parallel, membrane-traversing beta-strands. In this report, the outer-membrane localization model was confirmed by the structural and functional tolerance of PorT to hexahistidine (6xHis) tag insertions at selected locations within the protein using site-directed mutagenesis. Interestingly, those PorT mutations adversely affecting gingipain secretion enhanced

SUBMITTER: Nguyen KA 

PROVIDER: S-EPMC2729710 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature