Sequence analysis of the Porphyromonas gingivalis dipeptidyl peptidase IV gene

• Published in: Biochimica et biophysica acta 1998-03, Vol.1396 (1), p.39-46
• Main Authors: Kiyama, Michiko, Hayakawa, Mitsuo, Shiroza, Teruaki, Nakamura, Shoji, Takeuchi, Akira, Masamoto, Yukimitsu, Abiko, Yoshimitsu
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Cloning, Molecular; Dipeptidyl Peptidase 4 - genetics; Dipeptidyl peptidase IV; DNA, Complementary - isolation & purification; Flavobacterium; Humans; Mice; Molecular Sequence Data; Nucleotide sequence analysis; Porphyromonas gingivalis; Porphyromonas gingivalis - enzymology; Porphyromonas gingivalis - genetics; Protein Structure, Secondary; Rats; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Serine protease; Substrate Specificity
• ISSN: 0167-4781; 0006-3002; 1879-2634
• DOI: 10.1016/S0167-4781(97)00225-X

We previously constructed a Porphyromonas gingivalis genomic library and isolated the 2.9 kb EcoRV fragment which specified glycylprolyl dipeptidyl aminopeptidase (GPase). Nucleotide sequencing of this fragment identified the single 2169 bp open reading frame which coded for a 723 amino acid protein. The amino acid sequencing of the NH 2-terminal domain of the native and recombinant mature enzymes suggested that the protease possessed a 16 amino acid residue signal peptide. The calculated mass of the precursor and mature proteases were 82 018 and 80 235 daltons, respectively. The homology search of this enzyme in registered protein sequences revealed that this enzyme was homologous to dipeptidyl peptidase (DPP) IV from the Flavobacterium meningosepticum and that from eukaryotic cells, including the human, mouse, and rat. Three amino acid residues, Ser-593, Asp-668, and His-700, were identified as a putative catalytic triad, a common feature of eukaryotic serine proteases. In addition, this enzyme showed a broad proteolytic spectrum toward synthetic substrates capable of splitting not only Gly–Pro-derivative but also Ala–Pro, Lys–Pro, and Phe–Pro-derivatives. Therefore, we conclude that this enzyme belongs to DPP IV rather than GPase.