Construction and characterization of a nonpigmented mutant of Porphyromonas gingivalis: cell surface polysaccharide as an anchorage for gingipainsThe GenBank/EMBL/DDBJ accession number for the sequences reported in this paper is D64132. Shoji, Mikio and Ratnayake, Dinath B. and Shi, Yixin and Kadowaki, Tomoko and Yamamoto, Kenji and Yoshimura, Fuminobu and Akamine, Akifumi and Curtis, Michael A. and Nakayama, Koji,, 148, 1183-1191 (2002), doi = https://doi.org/10.1099/00221287-148-4-1183, publicationName = Microbiology Society, issn = 1350-0872, abstract= A nonpigmented mutant of Porphyromonas gingivalis was constructed by using transposon mutagenesis. The mutant possessed the transposon DNA at the novel gene porR. Gene targeted mutagenesis revealed that porR was responsible for pigmentation. The porR gene shared similarities with genes of the degT family, the products of which are now considered to be transaminases involved in biosynthesis of sugar portions of cell-surface polysaccharides and aminoglycosides. The porR mutant showed a pleiotropic phenotype: delayed maturation of fimbrillin, preferential presence of Rgp and Kgp proteinases in culture supernatants, and no haemagglutination. The porR mutant had altered phenol extractable polysaccharide compared to the porR + sibling strain. A mAb, 1B5, that reacts with sugar portions of P. gingivalis cell surface polysaccharide and membrane-type Rgp proteinase showed no reaction with the cell lysates of the porR mutant. These results indicate that porR is involved in biosynthesis of cell surface polysaccharide that may function as an anchorage for Rgp, Kgp, haemagglutinins and the haemoglobin receptor protein., language=, type=