초록 |
Our group has identified twenty-first aminoacyl-tRNA synthetase-suppressor tRNA pairs for possible use in site-specific incorporation of amino acid analogues into proteins in eukaryotes (E. coli glutaminyl-tRNA synthetase (GlnRS) / suppressor tRNAs derived from E. coli tRNAGln or human initiator tRNA) (1, 2). Our research goal is to identify mutants of E. coli GlnRS that can utilize the keto-containing glutamine analogue 2-amino-5-ketohexanoic acid (wherein the amide side chain of glutamine is replaced by a methyl ketone). The keto group can undergo a variety of reactions with hydrazides, alkoxyamines, and semicarbazides under physiological conditions. It can be used to produce proteins modified with fluorescent group, biotin, polyethylenglycol, saccharide and so on. To genetically encode 2-amino-5-ketohexanoic acid in yeast, we are working on isolation of the desired mutants of E. coli GlnRS using rational design and random mutagenesis of the active site. |