Cloning and nucleotide sequence of cDNA for rhodopsin of the squid Todarodes pacificus.
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.
Hara-Nishimura
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I
Department of Cell Biology, National Institute for Basic Biology, Okazaki, Japan.
Kondo
M
M
Nishimura
M
M
Hara
R
R
Hara
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004247:DNA; D049832:Decapodiformes; D008969:Molecular Sequence Data; D049831:Octopodiformes; D011487:Protein Conformation; D012243:Rhodopsin / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D004247:DNA; D012243:Rhodopsin