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The Shortest Nascent Peptide That Can Direct Ribosome Stalling
Author(s) -
sothiselvam shanmugapriya,
Ramu Haripriya,
Vazquez-Laslop Nora,
Mankin Alexander
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.550.3
Subject(s) - ribosome , translation (biology) , peptide , internal ribosome entry site , ribosomal rna , p site , transfer rna , biology , protein biosynthesis , rna , release factor , gene , ribosomal binding site , eukaryotic translation , stop codon , messenger rna , genetics , microbiology and biotechnology , start codon , biochemistry
An intrinsic property of the ribosome, an RNA machine, is to sense and functionally respond to the peptide being synthesized. In extreme cases, the ribosome halts translation while polymerizing specific peptides, forming a stalled complex at a precise codon on the translated ORF. Regulation of expression of inducible antibiotic resistance genes depends on such programmed translation arrest, controlled by the nascent peptide (generally 7–10 amino acids long) and an antibiotic bound to the ribosome. Macrolide resistance gene ermD is preceded by regulatory ORF ermDL encoding the peptide ‘MTHSMRLRFPTLNQ’ where stalling occurs at the Leu‐7 codon. By systematically shortening the ermDL ORF, we found that antibiotic‐promoted stalling can still be supported by the nascent peptide as short as ‘MRL’ with the peptidyl‐tRNA positioned in the P‐site. The identities of both the second and the A‐site codons of the shortened ORF are critical for stalling. We are determining the spectrum of inducing antibiotics and identity of the ribosomal RNA sensors that operate with the mini‐stalling peptide ‘MRL’. These data provide insights into the basic mechanisms of nascent peptide recognition and programmed translation arrest. This shortest version of the stalling peptide opens new venues for structural analysis of the stalled ribosome complexes.