Rice Genetics IV - IRRI books - International Rice Research Institute

ACRTSV (positive ssRNA)12,433 nt390 kCP1 CP2 CP3RRSV (dsRNA)PRO POLBORF4RTBV (dsDNA)IntergenicregionORF1ORF2?8,000 ntS10S9S8NS10 32 kP9 32 k SpikeP8B 47/44 kP8A 26 k Major capsidSegment sequencePredicted ORFSelf-cleaving siteRDRP motifs5’ GAUAAAGGUGC 3’RHRTORF3194kPROCPS7S6S5S4S3S2S1NS7 68 kP6 66 k?P5 91 k CapP4B 37 k?P4A 141 k RDRPP3 131 k Major coreP2 133 k?P1 137 k B spike?0 1 kb 2 kb 3 kb 4 kbGenome size = 26,066 ntD3’RSV (dsRNA)RNA 1200 k~9,000 nt3’ POL 5’RNA 2 3,514 nt94 k 23 k3’ 5’RNA 3 2,504 ntN 24 k3’ 5’RNA 4 2,154 nt32 k5 k5’ERYMV (positive ssRNA)Satellite RNA 220 nt5’ 4,550 nt3’14 k? 26 k CPORF3 ORF4ORF1ORF219 k? 101 k VPg:Protease:POLFig. 1. Genome organization of rice-infecting viruses. (A) RTSV has a single-stranded RNA genomethat is translated into one polyprotein and then cleaved by the viral protease (PRO) to produceCP1, CP2, and CP3 and an RNA-dependent RNA polymerase (POL). (B) RTBV has a double-strandedDNA genome that is transcribed to give an mRNA containing four open reading frames (ORFs). Apolyprotein encoded by ORF3 contains coat protein (CP), protease (PRO), reverse transcriptase(RT), and RNase H domains. (C) RRSV contains 10 dsRNA segments. Each contains an ORF,except S4, which contains two ORFs, of which one encodes an RNA-dependent RNA polymerase(RDRP). At least six of them encode structural proteins to make up the complex virus particle andtwo encode for nonstructural (NS) proteins. (D) RSV genome is either dsRNA or negative-sensesingle-stranded RNA that is made up of four segments. RNA1 encodes RDRP (POL) and the otherRNAs contain ORFs in both sense and negative-sense strands. (E) RYMV contains a single-strandednegative-sense RNA with four ORFs, with ORF2 encoding a polyprotein comprising a viral protease,the helicase, and the RDRP. ORF4 encodes the CP. ORF1 is required for viral replication and thefunction 412 Upadhyaya of ORF3 et is alyet to be determined.