Open AccessDissociation Rate of Cognate Peptidyl‐tRNA from the A‐Site of Hyper‐Accurate and Error‐Prone Ribosomes
Author(s) -
Karimi Reza,
Ehrenberg Måns
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb20059.x
Subject(s) - ribosome , streptomycin , neomycin , chemistry , a site , biochemistry , protein biosynthesis , translation (biology) , biology , biophysics , microbiology and biotechnology , binding site , rna , messenger rna , gene , antibiotics
The binding stability of the aminoacyl‐tRNA site (A‐site), estimated from the dissociation rate constant k d , of AcPhe‐Phe‐tRNA phe has been studied for wild‐type (wt), for hyperaccurate ribosomes altered in S12 [streptomycin‐dependent (SmD) and streptomycin‐pseudodependent (SmP) phenotypes], for error‐prone ribosomes altered in S4 (Ram phenotype), and for ribosomes in complex with the error‐inducing aminoglycosides streptomycin and neomycin. The AcPhe 2 ‐tRNA stability is slightly and identically reduced for SmD and SmP phenotypes in relation to wt ribosomes. The stability is increased ( k d is reduced) for Ram ribosomes to about the same extent as the proofreading accuracy is decreased for this phenotype. k d is also reduced by the action of streptomycin and neomycin, but much less than the reduction in proof‐reading accuracy induced by streptomycin. Similar k d values for SmD and SmP ribosomes indicate that the cause of streptomycin dependence is not excessive drop‐off of peptidyl‐tRNAs from the A‐site.