ABC50 mutants modify translation start codon selection

Joanna D. Stewart, Joanne L. Cowan, Lisa S. Perry, Mark J. Coldwell, Christopher G. Proud

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


ATP-binding cassette 50 (ABC50; also known as ABCF1) binds to eukaryotic initiation factor 2 (eIF2) and is required for efficient translation initiation. An essential step of this process is accurate recognition and selection of the initiation codon. It is widely accepted that the presence and movement of eIF1, eIF1A and eIF5 are key factors in modulating the stringency of startsite selection, which normally requires an AUG codon in an appropriate sequence context. In the present study, we show that expression of ABC50 mutants, which cannot hydrolyse ATP, decreases general translation and relaxes the discrimination against the use of non-AUG codons at translation start sites. These mutants do not appear to alter the association of key initiation factors to 40S subunits. The stringency of start-site selection can be restored through overexpression of eIF1, consistent with the role of that factor in enhancing stringency. The present study indicates that interfering with the function of ABC50 influences the accuracy of initiation codon selection.

Original languageEnglish
Pages (from-to)217-229
Number of pages13
JournalBiochemical Journal
Issue number2
Publication statusPublished or Issued - 15 Apr 2015


  • ABCF1
  • Accuracy
  • EIF2
  • Initiation factor
  • Start codon
  • Translation initiation

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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