Nonprotein amino acid furanomycin, unlike isoleucine in chemical structure, is charged to isoleucine tRNA by isoleucyl-tRNA synthetase and incorporated into protein.
Nonprotein amino acid furanomycin was found to bind with Escherichia coli isoleucyl-tRNA synthetase (IleRS) almost as tightly as the substrate L-isoleucine. The conformation of furanomycin bound to the enzyme was determined by NMR analyses including the transferred nuclear Overhauser effect method. The conformation of IleRS-bound furanomycin was similar to that of L-isoleucine, although the chemical structure of furanomycin is unlike that of L-isoleucine. By E. coli IleRS, E. coli tRNAIle was charged with furanomycin as efficiently as with L-isoleucine. Furthermore, furanomycyl-tRNAIle was bound to polypeptide chain elongation factor Tu as tightly as isoleucyl-tRNAIle. Furanomycin was found to be incorporated into beta-lactamase precursor by in vitro protein biosynthesis. A newly designed amino acid will probably be incorporated into proteins, provided that the new amino acid takes a similar conformation as a protein-constituting amino acid in the active site of an aminoacyl-tRNA synthetase.
Kohno
T
T
Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
Kohda
D
D
Haruki
M
M
Yokoyama
S
S
Miyazawa
T
T
D000596:Amino Acids / Q000378:metabolism*; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D007532:Isoleucine / Q000378:metabolism*; D007533:Isoleucine-tRNA Ligase / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008715:Methionine / Q000378:metabolism; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism*; D012355:RNA, Transfer, Ile / Q000378:metabolism*; D013379:Substrate Specificity
D000596:Amino Acids; D001426:Bacterial Proteins; D012345:RNA, Transfer, Amino Acid-Specific; D012355:RNA, Transfer, Ile; D007532:Isoleucine; C063753:furanomycin; D008715:Methionine; D000604:Amino Acyl-tRNA Synthetases; D007533:Isoleucine-tRNA Ligase