Hara-Nishimura I, Kondo M, Nishimura M, Hara R, Hara T
Department of Cell Biology, National Institute for Basic Biology, Okazaki, Japan.
FEBS Lett. 1993 Feb 8;317(1-2):5-11. doi: 10.1016/0014-5793(93)81480-n.
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.
从由太平洋褶柔鱼视网膜的聚腺苷酸加尾RNA构建的文库中分离出视紫红质的互补DNA（cDNA）。通过使用聚合酶链反应（PCR）扩增的cDNA片段作为探针，选择了一个插入片段最长（3.1 kb）的阳性克隆。该cDNA的核苷酸序列显示出一个1344 bp的单一开放阅读框，编码一个多肽（相对分子质量49833），其涵盖了鱿鱼视蛋白的完整序列。该克隆具有非常长的3'非编码区（1.7 kb），包括多个聚腺苷酸化信号AATAAA，类似于太平洋褶柔鱼视黄醛色素和视网膜结合蛋白（RALBP）的克隆。亲水性分析表明存在七个跨膜结构域，并且在第七个结构域中发现了一个可能的视网膜结合位点赖氨酸-305。如在枪乌贼和章鱼视紫红质中所报道的，太平洋褶柔鱼视紫红质在C末端区域含有重复的PPQGY特征序列。还讨论了那些头足类视紫红质的结构比较。
