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A glycine hinge for tRNA-dependent translocation of editing substrates to prevent errors by leucyl-tRNA synthetase.

ABSTRACT: Aminoacyl-tRNA synthetases often rely on a proofreading mechanism to clear mischarging errors before they can be incorporated into newly synthesized proteins. Leucyl-tRNA synthetase (LeuRS) houses a hydrolytic editing pocket in a domain that is distinct from its aminoacylation domain. Mischarged amino acids are transiently translocated approximately 30A between active sites for editing by an unknown tRNA-dependent mechanism. A glycine within a flexible beta-strand that links the aminoacylation and editing domains of LeuRS was determined to be important to tRNA translocation. The translocation-defective mutation also demonstrated that the editing site screens both correctly and incorrectly charged tRNAs prior to product release.

SUBMITTER: Mascarenhas AP

PROVIDER: S-EPMC2807821 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

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A glycine hinge for tRNA-dependent translocation of editing substrates to prevent errors by leucyl-tRNA synthetase.

Mascarenhas Anjali P AP Martinis Susan A SA

FEBS letters 20090929 21

Aminoacyl-tRNA synthetases often rely on a proofreading mechanism to clear mischarging errors before they can be incorporated into newly synthesized proteins. Leucyl-tRNA synthetase (LeuRS) houses a hydrolytic editing pocket in a domain that is distinct from its aminoacylation domain. Mischarged amino acids are transiently translocated approximately 30A between active sites for editing by an unknown tRNA-dependent mechanism. A glycine within a flexible beta-strand that links the aminoacylation a ...[more]

PMID: 19796639

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tRNA-dependent pre-transfer editing by prokaryotic leucyl-tRNA synthetase.

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