Structure and function in rhodopsin. Requirements of a specific structure for the intradiscal domain.

摘要: We concluded previously from mutagenesis in the intradiscal domain of bovine rhodopsin that formation a tertiary structure comprising N-terminal tail and three polypeptide loops is essential to vivo assembly functional rhodopsin. now report on more comprehensive mutagenic studies determine precisely requirement for above-proposed structure. Three large deletions, two consisting groups 10 amino acids each, third 34 acids, were carried out loop. All mutant opsins only poorly formed chromophore. In BC loop, we five 2 acid single mutations which short sequences loop reversed. resulting had lost ability bind 11-cis-retinal. DE where extensive been out, 3 replacements (Asn, Thr, Tyr) at Cys187. None these mutants bound FG, four 1 deletion, replacements, one mutation sequence 7 was FG partially described appeared be retained endoplasmic reticulum: several examined detail complexed with non-opsin proteins, chaperonins. Treatment ATP-MgCl2 released latter rhodopsins. Our overall conclusion specific has highly stringent spatial requirements.