Cloning and sequence analysis of a cDNA encoding salmon (Onchorhynchus keta) liver transglutaminase.
We isolated cDNA clones encoding a transglutaminase (TGase: EC 2.3.2.13) from a salmon (Onchorhynchus keta) cDNA library prepared from the liver. In the cDNA sequence combined, an open reading frame coding for a protein of 680 aa was found. The deduced sequence showed a considerable similarity (62.4%) to that of red sea bream TGase. By comparison of sequence similarity to other TGases, the structure of salmon TGase was like tissue type TGases, rather than membrane-associated type or plasma type TGases. As a structural feature of salmon TGase, 3 aa residues were substituted in the 25 aa sequence around the active site Cys residue, which is conserved among several tissue type TGases. The critical residues thought to form the catalytic-center triad (Cys272, His331, and Asp301) were found in the highly conserved region, but the region surrounding Tyr511, which corresponds to the residue participates in hydrogen-bond interactions of active center domain, was less similar to other TGases, except for red sea bream TGase. These finding suggests that the overall structure of fish TGase resembles tissue-type TGases, but has some unique structure.
Sano
K
K
Food Research and Development Laboratories, Ajinomoto Co., Inc, Kanagawa, Japan.
Nakanishi
K
K
Nakamura
N
N
Motoki
M
M
Yasueda
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000096:biosynthesis* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D017685:Oncorhynchus keta / Q000378:metabolism*; D010957:Plasmids; D011503:Transglutaminases / Q000096:biosynthesis* / Q000235:genetics*
D018076:DNA, Complementary; D011503:Transglutaminases