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Nascent peptide side chains induce rearrangements in distinct locations of the ribosomal tunnel.

ABSTRACT: Although we have numerous structures of ribosomes, none disclose side-chain rearrangements of the nascent peptide during chain elongation. This study reports for the first time that rearrangement of the peptide and/or tunnel occurs in distinct regions of the tunnel and is directed by the unique primary sequence of each nascent peptide. In the tunnel mid-region, the accessibility of an introduced cysteine to a series of novel hydrophilic maleimide reagents increases with increasing volume of the adjacent chain residue, a sensitivity not manifest at the constriction and exit port. This surprising result reveals molecular movements not yet resolvable from structural studies. These findings map solvent-accessible volumes along the tunnel and provide novel insights critical to our understanding of allosteric communication within the ribosomal tunnel, translational arrest, chaperone interaction, folding, and rates of elongation.

SUBMITTER: Lu J

PROVIDER: S-EPMC3143575 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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Nascent peptide side chains induce rearrangements in distinct locations of the ribosomal tunnel.

Lu Jianli J Hua Zhengmao Z Kobertz William R WR Deutsch Carol C

Journal of molecular biology 20110601 2

Although we have numerous structures of ribosomes, none disclose side-chain rearrangements of the nascent peptide during chain elongation. This study reports for the first time that rearrangement of the peptide and/or tunnel occurs in distinct regions of the tunnel and is directed by the unique primary sequence of each nascent peptide. In the tunnel mid-region, the accessibility of an introduced cysteine to a series of novel hydrophilic maleimide reagents increases with increasing volume of the ...[more]

PMID: 21663746

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