The elongation factor Tu.GTPase reaction: effect of 2'(3')-O-aminoacyl oligoribonucleotides.
The activity of synthetic (2'(3')-O-aminoacyl trinucleotides, C-C-A-Phe, C-C-U-Phe, C-U-A-Phe, U-C-A-Phe and C-A-A-Phe, in promoting the EF-Tu.70 S ribosome-catalyzed GTP hydrolysis was investigated. It was found that the activity decreases in the order C-C-A-Phe greater than C-U-A-Phe greater than U-C-A-Phe greater than C-A-A-Phe much greater than C-C-U-Phe. Thus, the substitution in 'natural' C-C-A sequence with other nucleobases weakens binding of 2'(3')-O-aminoacyl trinucleotides to EF-Tu, with the substitution at the 3'-position having the most profound effect. Since the 2'(3')-O-aminoacyl oligonucleotides mimic the effect of the aa-tRNA 3'-terminus on EF-Tu.GTPase, it follows that EF-Tu probably directly recognizes structure of nucleobases in the aa-tRNA 3'-terminus, with the 3'-terminal adenine playing the most important role.
Tezuka
M
M
Department of Chemistry, Michigan Cancer Foundation, Detroit 48201.
Chládek
S
S
D020963:GTP Phosphohydrolase-Linked Elongation Factors / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D009843:Oligoribonucleotides / Q000494:pharmacology*; D010444:Peptide Elongation Factor Tu / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011485:Protein Binding; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism
D009843:Oligoribonucleotides; D006160:Guanosine Triphosphate; D010744:Phosphoric Monoester Hydrolases; D020963:GTP Phosphohydrolase-Linked Elongation Factors; D010444:Peptide Elongation Factor Tu