Unique double-stranded RNAs responsible for the anti-Candida activity of the yeast Hanseniaspora uvarum.
Killer strains of the yeast Hanseniaspora uvarum contain cytoplasmic double-stranded RNAs (dsRNAs) of 4.7-kbp L and 1.0-kbp M species, which were shown to be separately packaged into icosahedral virus-like particles exhibiting RNA-dependent RNA polymerase activity. The L genome of the H. uvarum L-dsRNA virion HuV-L was shown to encode a 77-kDa major capsid protein. Peptide maps of the purified HuV coat protein and the 81-kDa major capsid protein from K1 killer viruses of Saccharomyces cerevisiae revealed distinctly different peptide patterns, suggesting significant sequence divergence at the level of the capsid-coding L-dsRNAs. In vitro transcripts from purified HuV-L particles showed no cross-hybridization to denatured L(A), L(B), or L(C), indicating that L from H. uvarum represents a unique L-dsRNA species. Weak, but clearly detectable cross-hybridization of the 1.0-kb dsRNA of HuV-M, encoding the secreted 18-kDa anti-Candida toxin, to the toxin-coding M genomes of S. cerevisiae K1, K2, and K28 killers indicated partial sequence homology among all of the M-dsRNAs tested.
Schmitt
M J
MJ
Abteilung Angewandte Molekularbiologie, Institut für Mikrobiologie, Universität des Saarlandes, Saarbrücken, Germany. mjs@microbiol.uni-sb.de
Poravou
O
O
Trenz
K
K
Rehfeldt
K
K
D002175:Candida; D002213:Capsid / Q000737:chemistry; D003001:Cloning, Molecular; D010449:Peptide Mapping; D012328:RNA Viruses / Q000235:genetics*; D012330:RNA, Double-Stranded / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D015003:Yeasts / Q000821:virology*
D012330:RNA, Double-Stranded; D012324:RNA-Dependent RNA Polymerase