Tauropine dehydrogenase from the marine sponge Halichondria japonica is a homolog of ornithine cyclodeaminase/mu-crystallin.
The partial amino acid sequence including the N- and C-terminal portions of tauropine dehydrogenase (EC 1.5.1.23) from the marine sponge Halichondria japonica was determined by enzymatic cleavages followed by peptide sequencing. This information was used to design degenerate primers for amplification of cDNA encoding the tauropine dehydrogenase. The cDNA included 1231 nucleotides with an open reading frame of 1002 nucleotides that encodes a protein of 334 amino acid residues. From the peptide and nucleotide sequencing, the mature tauropine dehydrogenase was estimated to consist of 333 amino acid residues with an acetylated N-terminal serine residue and no intrachain disulfide bonds. The primary structure of the H. japonica enzyme showed apparent similarity with a homolog of ornithine cyclodeaminase from Rhizobium meliloti and other proteins of the ornithine cyclodeaminase/mu-crystallin family, but it showed no significant similarity with the known sequences of octopine dehydrogenases and tauropine dehydrogenases from marine invertebrates. These findings indicate that opine dehydrogenases in marine invertebrates are not all homologous.
Kan-No
Nobuhiro
N
Department of Marine Biosciences, School of Fisheries Sciences, Kitasato University Sanriku 160-4, Ohfunato, Iwate 022-0101, Japan. kan-no@kitasato-u.ac.jp
Matsu-Ura
Hiroto
H
Jikihara
Shinya
S
Yamamoto
Takayuki
T
Endo
Noriyuki
N
Moriyama
Shunsuke
S
Nagahisa
Eizoh
E
Sato
Minoru
M
D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000642:Ammonia-Lyases / Q000737:chemistry*; D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D003459:Crystallins / Q000737:chemistry*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011161:Porifera / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D000090803:mu-Crystallins
D003459:Crystallins; D018076:DNA, Complementary; D010446:Peptide Fragments; D000594:Amino Acid Oxidoreductases; C050564:tauropine dehydrogenase; C021903:D-octopine dehydrogenase; D000090803:mu-Crystallins; D000642:Ammonia-Lyases; C021914:ornithine cyclodeaminase