The Q motif: a newly identified motif in DEAD box helicases may regulate ATP binding and hydrolysis.
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.
Tanner
N Kyle
NK
Département de Biochimie Médicale, Centre Médical Universitaire, 1, rue Michel Servet, 1211 Geneva 4, Switzerland. kyle.tanner@medecine.unige.ch
Cordin
Olivier
O
Banroques
Josette
J
Doère
Monique
M
Linder
Patrick
P
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002470:Cell Survival; D016384:Consensus Sequence; D003432:Cross-Linking Reagents / Q000378:metabolism; D039601:Eukaryotic Initiation Factor-4A / Q000235:genetics / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D010641:Phenotype; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D003432:Cross-Linking Reagents; D029701:Saccharomyces cerevisiae Proteins; D005973:Glutamine; D000255:Adenosine Triphosphate; D039601:Eukaryotic Initiation Factor-4A; D000251:Adenosine Triphosphatases; D020365:RNA Helicases