A 35-kDa co-aggregation factor is a hemin binding protein in Porphyromonas gingivalis

• Published in: Biochemical and biophysical research communications 2003-01, Vol.300 (2), p.351-356
• Main Authors: Shibata, Yasuko, Hiratsuka, Koichi, Hayakawa, Mitsuo, Shiroza, Teruaki, Takiguchi, Hisashi, Nagatsuka, Yasuko, Abiko, Yoshimitsu
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacterial Outer Membrane Proteins - metabolism; Bacterial Outer Membrane Proteins - physiology; Base Sequence; Carrier Proteins - metabolism; Carrier Proteins - physiology; Hemeproteins - metabolism; Hemeproteins - physiology; Hemin - metabolism; Hemin binding; Molecular Sequence Data; P. gingivalis; Periodontal diseases; Porphyromonas gingivalis - pathogenicity; Protoporphyrins - metabolism; Virulence factors; Virulence Factors - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)02826-7

It has been known that Porphyromonas gingivalis has an obligate requirement for hemin or selected heme- or Fe-containing compounds for its growth. In addition, the influence of hemin on the expression of several putative virulence factors produced by this bacterium has also been recently documented; however, the mechanisms involved in hemin uptake are poorly defined. We succeeded in cloning the gene coding for the 35-kDa protein, which was specifically expressed in P. gingivalis and seemed to confer colonizing activities. Recently, we have constructed the P. gingivalis 381 mutant defective in the 35-kDa protein by insertion mutagenesis. The beige mutant exhibited little co-aggregation and the virulence was also decreased. Based on these results and homology search analysis, we focused on assessing the hemin bindings and found the heme regulatory motif (HRM) as a hemin direct binding site. The 35-kDa protein did possess the binding ability of selected protoporphyrins involving the hemin. These results demonstrated that 35-kDa protein is one of the hemin binding proteins in P. gingivalis and suggested that hemin binding ability of 35-kDa protein is important for the expression of virulence in P. gingivalis.