부산대학교 도서관

ABSTRACTThe Porphyromonas gingivalisVimA protein has multifunctional properties that can modulate several of its major virulence factors. To further characterize VimA, P. gingivalisFLL406 carrying an additional vimAgene and a vimA-defective mutant in a different P. gingivalisgenetic background were evaluated. The vimA-defective mutant (FLL451) in the P. gingivalisATCC 33277 genetic background showed a phenotype similar to that of the vimA-defective mutant (FLL92) in the P. gingivalisW83 genetic background. In contrast to the wild type, gingipain activity was increased in P. gingivalisFLL406, a vimAchimeric strain. P. gingivalisFLL451 had a five times higher biofilm-forming capacity than the parent strain. HeLa cells incubated with P. gingivalisFLL92 showed a decrease in invasion, in contrast to P. gingivalisFLL451 and FLL406, which showed increases of 30 and 40%, respectively. VimA mediated coenzyme A (CoA) transfer to isoleucine and reduced branched-chain amino acid metabolism. The lipid A content and associated proteins were altered in the vimA-defective mutants. The VimA chimera interacted with several proteins which were found to have an LXXTG motif, similar to the sorting motif of Gram-positive organisms. All the proteins had an N-terminal signal sequence with a putative sorting signal of L(P/T/S)X(T/N/D)G and two unique signatures of EXGXTX and HISXXGXG, in addition to a polar tail. Taken together, these observations further confirm the multifunctional role of VimA in modulating virulence possibly through its involvement in acetyl-CoA transfer and lipid A synthesis and possibly by protein sorting.