title: Unaltered expression of the major protease genes in a non-virulent recA-defective mutant of Porphyromonas gingivalis W83.
abstract: Porphyromonas gingivalis FLL32, a recA mutant, was isolated during construction of a recA defective mutant of P. gingivalis W83 by allelic exchange mutagenesis. In contrast to W83 and FLL33, the typical recA- mutant previously reported, FLL32 was non-pigmented, lacked beta-hemolytic activity on blood agar and produced significantly less proteolytic activity. The proteolytic activity in FLL32 was mostly soluble. Expression of the rgpA, rgpB and kgp protease genes was unaltered in FLL32 when compared to FLL33 and the wild-type strain. FLL32 exhibited reduced virulence in a murine model and partially protected the animals immunized with that strain against a subsequent lethal challenge by the wild-type strain. These results indicate that the reduced level of proteolytic activity in FLL32 may be due to a defect in the processing of the proteases. Further, immunization with a non-virulent recA defective mutant of P. gingivalis can partially protect against a lethal wild-type challenge. The results from this study suggest that the recA locus may be involved in expression and regulation of proteolytic activity in P. gingivalis.
authors.affiliation: Department of Microbiology and Molecular Genetics, Loma Linda University, Loma Linda, California 92350, USA.
authors.forename: H
authors.initials: H
authors.lastname: Abaibou
authors.forename: Q
authors.initials: Q
authors.lastname: Ma
authors.forename: G J
authors.initials: GJ
authors.lastname: Olango
authors.forename: J
authors.initials: J
authors.lastname: Potempa
authors.forename: J
authors.initials: J
authors.lastname: Travis
authors.forename: H M
authors.initials: HM
authors.lastname: Fletcher
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D016009:Chi-Square Distribution; D004591:Electrophoresis, Polyacrylamide Gel; D018274:Electroporation; D010450:Endopeptidases / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D016254:Mutagenesis, Insertional; D016966:Porphyromonas gingivalis / Q000201:enzymology* / Q000235:genetics* / Q000472:pathogenicity; D011938:Rec A Recombinases / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014774:Virulence
chemical_list: D011938:Rec A Recombinases; D010450:Endopeptidases