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Updated: Sep 5, 2026

A G-quadruplex DNA-affinity Approach for Purification of Enzymatically Active G4 Resolvase1
Published on: March 18, 2017
The Q motif: a newly identified motif in DEAD box helicases may regulate ATP binding and hydrolysis
N Kyle Tanner1, Olivier Cordin, Josette Banroques
1Département de Biochimie Médicale, Centre Médical Universitaire, 1, rue Michel Servet, 1211 Geneva 4, Switzerland. kyle.tanner@medecine.unige.ch
Abstract:
SF1 and SF2 helicases have structurally conserved cores containing seven to eight distinctive motifs and variable amino- and carboxyl-terminal flanking sequences. We have discovered a motif upstream of motif I that is unique to and characteristic of the DEAD box family of RNA helicases. It consists of a 9 amino acid sequence containing an invariant glutamine. A conserved phenylalanine occurs 17 aa further upstream. Sequence alignments, site-specific mutagenesis, and ATPase assays show that this motif and the upstream phenylalanine are highly conserved, that they are essential for viability in the yeast Saccharomyces cerevisiae, and that they control ATP binding and hydrolysis in the yeast translation-initiation factor eIF4A. These results are consistent with computer studies of the solved crystal structures.
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