A neutron scattering study of the ternary complex EF-Tu.GTP-valyl-tRNAVal1A.
The complex formation between elongation factor Tu (EF-Tu), GTP, and valyl-tRNAVal1A has been investigated in a hepes buffer of "pH" 7.4 and 0.2 M ionic strength using the small-angle neutron scattering method at concentrations of D2O where EF-Tu (42% D2O) and tRNA (71% D2O) are successively matched by the solvents. The results indicate that EF-Tu undergoes a conformational change and contracts as a result of the complex formation, since the radius of gyration decreases by 15% from 2.82 to 2.39 nm. tRNAVal1A, on the other hand, seems to mainly retain its conformation within the complex, since the radii of gyration for the free (after correction for interparticular scattering) and complexed form are essentially the same, 2.38 and 2.47 nm, respectively.
Osterberg
R
R
Department of Chemistry and Molecular Biology, Swedish Univ. of Agricultural Sciences, Uppsala.
Elias
P
P
Kjems
J
J
Bauer
R
R
D001665:Binding Sites; D006160:Guanosine Triphosphate; D009502:Neutrons; D010444:Peptide Elongation Factor Tu; D012345:RNA, Transfer, Amino Acid-Specific; D012346:RNA, Transfer, Amino Acyl; D012366:RNA, Transfer, Val; D012542:Scattering, Radiation
D012345:RNA, Transfer, Amino Acid-Specific; D012346:RNA, Transfer, Amino Acyl; D012366:RNA, Transfer, Val; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu