The human coronavirus 229E superfamily 1 helicase has RNA and DNA duplex-unwinding activities with 5'-to-3' polarity.
The human coronavirus 229E replicase gene encodes a protein, p66HEL, that contains a putative zinc finger structure linked to a putative superfamily (SF) 1 helicase. A histidine-tagged form of this protein, HEL, was expressed using baculovirus vectors in insect cells. The purified recombinant protein had in vitro ATPase activity that was strongly stimulated by poly(U), poly(dT), poly(C), and poly(dA), but not by poly(G). The recombinant protein also had both RNA and DNA duplex-unwinding activities with 5'-to-3' polarity. The DNA helicase activity of the enzyme preferentially unwound 5'-oligopyrimidine-tailed, partial-duplex substrates and required a tail length of at least 10 nucleotides for effective unwinding. The combined data suggest that the coronaviral SF1 helicase functionally differs from the previously characterized RNA virus SF2 helicases.
Institute of Virology and Immunology, University of Würzburg, Germany.
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Seybert
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Hegyi
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Siddell
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Ziebuhr
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D016367:Baculoviridae / Q000378:metabolism; D001483:Base Sequence; D002846:Chromatography, Affinity; D017934:Coronavirus / Q000201:enzymology*; D028941:Coronavirus 229E, Human; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D006639:Histidine / Q000378:metabolism; D007313:Insecta / Q000378:metabolism; D008969:Molecular Sequence Data; D017354:Point Mutation; D011119:Polynucleotides / Q000494:pharmacology; D020365:RNA Helicases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins
D011119:Polynucleotides; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; D006639:Histidine; D004247:DNA; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D020365:RNA Helicases; C412015:p66HEL protein, Human coronavirus 229E