A transcriptionally active subgenomic promoter supports homologous crossovers in a plus-strand RNA virus.
Genetic RNA recombination plays an important role in viral evolution, but its molecular mechanism is not well understood. In this work we describe homologous RNA recombination activity that is supported by a subgenomic promoter (sgp) region in the RNA3 segment of brome mosaic bromovirus (BMV), a tripartite plus-strand RNA virus. The crossover frequencies were determined by coinoculations with pairs of BMV RNA3 variants that carried a duplicated sgp region flanked by marker restriction sites. A region composed of the sgp core, a poly(A) tract, and an upstream enhancer supported homologous exchanges in 25% of the analyzed RNA3 progeny. However, mutations in the sgp core stopped both the transcription of the sgp RNA and homologous recombination. These data provide evidence for an association of RNA recombination with transcription.
Wierzchoslawski
Rafal
R
Plant Molecular Biology Center, Department of Biological Sciences, Northern Illinois University, De Kalb, Illinois 60115, USA.
Dzianott
Aleksandra
A
Kunimalayan
Selvi
S
Bujarski
Jozef J
JJ
D017795:Bromovirus / Q000235:genetics* / Q000472:pathogenicity; D027465:Chenopodium quinoa / Q000821:virology; D003434:Crossing Over, Genetic; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D009154:Mutation; D010935:Plant Diseases / Q000821:virology; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000096:biosynthesis; D014158:Transcription, Genetic
D012367:RNA, Viral