Conformational change of mammalian tyrosyl-tRNA synthetase induced by tyrosyl adenylate formation.
The fluorescent probe 1,5-I-AEDANS was covalently attached to bovine tyrosyl-tRNA synthetase outside of enzyme active site in a nearly stoichiometric amount (2 probe molecules per enzyme dimer). Singlet-singlet resonance energy transfer has been used for the measurement of the apparent distance between tryptophan residues of enzyme and covalently attached 1,5-I-AEDANS. This distance was estimated as 27.4 A in the assumption of the random orientation of the donor and acceptor fluorophores. Tyrosyl adenylate formation catalyzed by bovine tyrosyl-tRNA synthetase resulted in the highly specific enhancement of 1,5-I-AEDANS fluorescence and concomitant decrease of the apparent distance between the probe and tryptophanyls to 22.3-25.7 A. These results are consistent with the conformational change of tyrosyl-tRNA synthetase during tyrosyl adenylate formation which propagates to distant from active site regions of enzyme structure.
Kornelyuk
A I
AI
Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kiev.
Klimenko
I V
IV
Odynets
K A
KA
D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004735:Energy Transfer; D005456:Fluorescent Dyes; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008322:Mammals; D008433:Mathematics; D009282:Naphthalenesulfonates; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism; D014448:Tyrosine-tRNA Ligase / Q000737:chemistry* / Q000378:metabolism*
D005456:Fluorescent Dyes; D009282:Naphthalenesulfonates; D000249:Adenosine Monophosphate; D014443:Tyrosine; C019586:tyrosinyl-5'-AMP; C006421:1,5-I-AEDANS; D014448:Tyrosine-tRNA Ligase