Cloning and sequencing a HemK-family gene in Porphyromonas gingivalis.
HemK, a universally conserved protein of unknown function, has high amino acid similarity with DNA-(adenine-N6) methyltransferases (MTases). In the present study, we sequenced a 5026 bp DNA fragment just downstream of the PgPepO gene reported previously. The DNA sequence analysis revealed three ORFs. The ORF2 gene encoded a protein of 294 amino acids with a calculated molecular weight of 32,160 Da. The deduced amino acid sequence of the ORF2 gene exhibited a significant similarity to sequence of HemK from E. coli (35% identical residues). The ORF2 gene complemented an E. coli hemK mutant. Thus, ORF2 was named PgHemK. From the point of veiw of our recent finding, that E. coli HemK catalyses the methylation of polypeptide chain release factors such as RF1 and RF2, we postulated that PgHemK might function as a protein MTase containing the DNA MTase motif.
Department of Preventive Dentistry, Kyushu Dental College, Kokurakita-ku, Kitakyushu 803-8580, Japan.
Akito
A
Kusaba
Toshihiro
T
Ansai
Sumio
S
Akifusa
Kenji
K
Nakahigashi
Hachiro
H
Inokuchi
Tadamichi
T
Takehara
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D005816:Genetic Complementation Test; D008780:Methyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D016966:Porphyromonas gingivalis / Q000201:enzymology / Q000235:genetics*; D011496:Protein Methyltransferases / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; C477348:HemK protein, Porphyromonas gingivalis; D008780:Methyltransferases; D011496:Protein Methyltransferases