Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 9
Book Description
Killer virus of Saccharomyces cerevisiae is a cytoplasmically- inherited virus that confers on persistently-infected yeast cells the ability to secrete a protein toxin which kills uninfected yeast cells but to which infected cells, denoted killers, are resistant (reviewed by Tipper and Bostian, 1984; Wickner, 1986). Killer toxin production can be assayed by halos of killing of a lawn of uninfected cells around killer colonies on a petri dish. The genome of the virus consists of two segments of double-stranded (ds) RNA that are separately encapsidated in cytoplasmic virions localized in the cytoplasm of infected cells. The L-A dsRNA segment is 4.9 kbp in length and encodes the major capsid protein (81 kd) of the virions and possibly a larger capsid-RNA polymerase fusion product by a -1 frame shift occurring at the translational level, analogous to that producing retrovirus gag-pol fusion protein (Icho and Wickner, 1988; Diamond et al, 1989).
