Detection of dsRNA-binding domains in RNA helicase A and Drosophila maleless: implications for monomeric RNA helicases.
Searches with dsRNA-binding domain profiles detected two copies of the domain in each of RNA helicase A, Drosophila maleless and C. elegans ORF T20G5-11 (of unknown function). RNA helicase A is unusual in being one of the few characterised DEAD/DExH helicases that are active as monomers. Other monomeric DEAD/DExH RNA helicases (p68, NPH-II) have domains that match another RNA-binding motif, the RGG repeat. The DEAD/DExH domain appears to be insufficient on its own to promote helicase activity and additional RNA-binding capacity must be supplied either as domains adjacent to the DEAD/DExH-box or by bound partners as in the eIF-4AB dimer. The presence or absence of extra RNA-binding domains should allow classification of DEAD/DExH proteins as monomeric or multimeric helicases.
Gibson
T J
TJ
European Molecular Biology Laboratory, Heidelberg, Germany.
Thompson
J D
JD
D000595:Amino Acid Sequence; D000818:Animals; D002868:Chromosomal Proteins, Non-Histone; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D016208:Databases, Factual; D004330:Drosophila / Q000201:enzymology / Q000235:genetics*; D029721:Drosophila Proteins; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D020365:RNA Helicases; D012316:RNA Nucleotidyltransferases / Q000378:metabolism*; D012330:RNA, Double-Stranded / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000378:metabolism*
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012330:RNA, Double-Stranded; D014157:Transcription Factors; C070837:mle protein, Drosophila; D012316:RNA Nucleotidyltransferases; D004265:DNA Helicases; D020365:RNA Helicases