CSB351Y1 Study Guide - Rna Virus, Reverse Transcriptase, Plant Virus

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Document Summary

The 35s rna is particularly complex, containing highly structured 600 nt long leader sequence with 6-8 short orf (encode proteins 2-35 aa in length) This leader is followed by 7 tightly arranged longer orfs that encode all the viral proteins. The mechanism of expression of these proteins is very special. Orf vi protein (tav, encoded by the 19s rna) controls translation reinitiation of major. The replication is similar to that of other retroviruses. The 35s rna contains at the 5" end region 13 nt complementary to the. 3" end of trna met and 190 nt of repeated sequences at the two ends of the rna. The 3" oh end of the trna met is used as a primer for the reverse transcriptase to start the synthesis of a complementary dna of the virus. The ribonuclease h activity of the rt degrades the rna hybridised to the cdna. However, small pieces of rna are resistant to the rnase h activity.