A kinetic framework for tRNA ligase and enforcement of a 2'-phosphate requirement for ligation highlights the design logic of an RNA repair machine Journal Article


Authors: Remus, B. S.; Shuman, S.
Article Title: A kinetic framework for tRNA ligase and enforcement of a 2'-phosphate requirement for ligation highlights the design logic of an RNA repair machine
Abstract: tRNA ligases are essential components of informational and stress-response pathways entailing repair of RNA breaks with 2',3'-cyclic phosphate and 5'-OH ends. Plant and fungal tRNA ligases comprise three catalytic domains. Phosphodiesterase and kinase modules heal the broken ends to generate the 3'-OH, 2'-PO4, and 5'-PO4 required for sealing by the ligase. We exploit RNA substrates with different termini to define rates of individual steps or subsets of steps along the repair pathway of plant ligase AtRNL. The results highlight rate-limiting transactions, how repair is affected by active-site mutations, and how mutations are bypassed by RNA alterations. We gain insights to 2'-PO4 specificity by showing that AtRNL is deficient in transferring AMP to pRNAOH to form AppRNAOH but proficient at sealing pre-adenylylated AppRNAOH. This strategy for discriminating 2'-PO 4 versus 2'-OH ends provides a quality-control checkpoint to ensure that only purposeful RNA breaks are sealed and to avoid nonspecific "capping" of 5'-PO4 ends. Copyright © 2013 RNA Society.
Keywords: unclassified drug; in vitro study; enzyme activity; wild type; kinetics; catalysis; enzyme kinetics; chemical reaction; trna splicing; polynucleotide kinase; rna repair; rna ligase; phosphodiesterase; trna ligase; 2',3' cyclic phosphodiesterase; cyclic phosphodiesterase; rna quality control
Journal Title: RNA
Volume: 19
Issue: 5
ISSN: 1355-8382
Publisher: Cold Spring Harbor Laboratory Press  
Date Published: 2013-05-01
Start Page: 659
End Page: 669
Language: English
DOI: 10.1261/rna.038406.113
PROVIDER: scopus
PUBMED: 23515942
PMCID: PMC3677281
DOI/URL:
Notes: --- - "Export Date: 3 June 2013" - "CODEN: RNARF" - "Source: Scopus"
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  1. Stewart H Shuman
    548 Shuman
  2. Barbara Remus
    6 Remus