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Cloning and nucleotide sequence of cDNA for rhodopsin of the squid Todarodes pacificus
Author(s) -
Hara-Nishimura Ikuko,
Kondo Maki,
Nishimura Mikio,
Hara Reiko,
Hara Tomiyuki
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81480-n
Subject(s) - rhodopsin , complementary dna , biology , transmembrane domain , cdna library , microbiology and biotechnology , polyadenylation , open reading frame , genetics , peptide sequence , rna , gene , biochemistry , retinal
A cDNA for rhodopsin was isolated from a library constructed from poly(A) + RNA of the squid ( Todarodes pacificus ) retina. One positive clone with the longest insert of cDNA (3.1 kb) was selected by employing a PCR‐amplified cDNA fragment as a probe. The nucleotide sequence of the cDNA revealed a single open reading frame of 1,344 bp encoding a polypeptide ( M r , 49,833), which covered a complete sequence for the squid opsin. This clone had a very long 3'‐non‐coding region (1.7 kb) including multiple polyadenylation signals, AATAAA, resembling the clones for Todarodes retinochrome and retinal‐binding protein (RALBP). The analysis of hydropathicity demonstrated the presence of seven transmembrane spanning domains, and a possible retinal‐binding site, Lys‐305, was found in the 7th domain. Todarodes rhodopsin contained characteristic sequences of PPQGY repeated in the C‐terminal region, as reported in Loligo and octopus rhodopsins. Structural comparison of those cephalopod rhodopsins is also discussed.