Translation rate for short peptides

Value 22 1/sec Range: Table - link 1/sec
Organism Bacteria Escherichia coli
Reference Bilgin N, Claesens F, Pahverk H, Ehrenberg M. Kinetic properties of Escherichia coli ribosomes with altered forms of S12. J Mol Biol. 1992 Apr 20 224(4):1011-27. p.1020 table 3PubMed ID1569565
Method "A quench-flow device with a time resolution of about one millisecond is used to start elongation by rapidly mixing initiated ribosomes with ternary complex and to quench the reaction at different time points after mixing. With this technique researchers have characterized different steps during the translation cycle of wild-type ribosomes, such as GTP hydrolysis on EF-Tu and dipeptide formation. [Researchers] have used the same technique to study the time evolution of the first few elongation cycles of poly(Phe) synthesis [Researchers] have, in particular, investigated how mutations in the ribosomal protein S12 or the presence of Sm influence different steps in the ribosomal elongation cycle." "[For measurement method of elongation rates,] the reaction was stopped with 20% formic acid and the amounts of di-, tri- and tetrapeptides were measured at different time points with h.p.l.c. technique (Materials and Methods). From the time evolution of these peptides, the rate of poly(Phe) synthesis during the first few cycles of translation was estimated (Table 3)."
Comments "This analysis indicates that wild-type ribosomes have a kcat near 22 s^-1, SmR ribosomes near 16 s^-1, SmP near 11 s^-1 and SmD about 3 s^-1. In the presence of Sm, SmP and SmD ribosomes have, as before, kcat values near 10 s^-1." See BNID 100059,100233
Entered by Uri M
ID 105067