A 35-kDa co-aggregation factor is a hemin binding protein in Porphyromonas gingivalis.
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.
Shibata
Yasuko
Y
Department of Biochemistry, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
Hiratsuka
Koichi
K
Hayakawa
Mitsuo
M
Shiroza
Teruaki
T
Takiguchi
Hisashi
H
Nagatsuka
Yasuko
Y
Abiko
Yoshimitsu
Y
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism* / Q000502:physiology; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism* / Q000502:physiology; D000081062:Heme-Binding Proteins; D006420:Hemeproteins / Q000378:metabolism* / Q000502:physiology; D006427:Hemin / Q000378:metabolism*; D008969:Molecular Sequence Data; D016966:Porphyromonas gingivalis / Q000472:pathogenicity*; D011524:Protoporphyrins / Q000378:metabolism; D037521:Virulence Factors / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D000081062:Heme-Binding Proteins; D006420:Hemeproteins; D011524:Protoporphyrins; D037521:Virulence Factors; D006427:Hemin