서강대학교

초록/요약

Microbial rhodopsin is well-known seven-transmembrane proteins that have been extensively studied. These retinal-binding proteins have divided into two types. The type I is microbial rhodopsins, and type II (visual pigment) is expressed mostly in mammalian eyes. For type I rhodopsin, there are two main functions that are ion pumping activity and sensory transduction. Anabaena sensory rhodopsin (ASR) is one of the microbial rhodopsin with main function as photo-sensory transduction. Since, ASR is expressed fairly well, but it is much less expressed in Escherichia coli compare to Proteorhodopsin. In this study, full length of ASR was used to test for the expression influenced by codon usage in E. coli. Eight amino acids of codon at N-terminal part of ASR were changed randomly with designed primers which allow 8,192 nucleotide different cases. The codon changes were screened for the preferable codons of each residues which have given higher expression yield. Among those 57 selected mutations, there are 24 color-enhanced E. coli colonies that contain ASR proteins and it showed better expression level than the wild type ASR codon usage.