Open AccessFunctional investigation of residue G791 of Escherichia coli 16S rRNA: implication of initiation factor 1 in the restoration of P‐site function
Author(s) -
Song WooSeok,
Ryou SangMi,
Kim HongMan,
Jeon Che Ok,
Kim JongMyung,
Han Seung Hyun,
Kim Si Wouk,
Szatkiewicz Jin P.,
Cunningham Philip R.,
Lee Kangseok
Publication year - 2010
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2010.02137.x
Subject(s) - ribosome , biology , eukaryotic ribosome , mutant , ribosomal rna , ribosomal protein , initiation factor , protein biosynthesis , protein subunit , biochemistry , escherichia coli , eukaryotic large ribosomal subunit , microbiology and biotechnology , rna , gene
Using a specialized ribosome system, previous studies have identified G791 in Escherichia coli 16S rRNA as an invariant and essential residue for ribosome function. To investigate the functional role of G791, we searched for multicopy suppressors that partially restored the protein synthesis ability of mutant ribosomes bearing a G to U substitution at position 791 (U791 ribosomes). Analyses of isolated multicopy suppressors showed that overexpression of initiation factor 1 (IF1) enhanced the protein synthesis ability of U791 ribosomes. In contrast, overexpression of initiation factor 2 (IF2) or IF3 did not enhance the protein synthesis ability of wild‐type or U791 ribosomes, and overexpression of IF1 did not affect the function of wild‐type or mutant ribosomes bearing nucleotide substitutions in other regions of 16S rRNA. Analyses of sucrose gradient profiles of ribosomes showed that overexpression of IF1 marginally enhanced the subunit association of U791 ribosomes and indicated lower binding affinity of U791 ribosomes to IF1. Our findings suggest the involvement of IF1 in the restoration of the P‐site function that was impaired by a nucleotide substitution at residue G791.