Coronavirus: A Jumping RNA Transcription

Abstract

DNA- and RNA-dependent RNA polymerases usually recognize specific promoter sequences and initiate RNA transcription at some distances downstream from the promoter. Initiation of transcription requires only complementary nucleoside triphosphates, although oligonucleotides could, under some conditions, act as primers for transcription (Niyogi and Stevens 1965; Minkley and Pribnow 1973). An exception to this general rule is the RNA-dependent RNA polymerase of influenza virus, which utilizes capped mRNAs derived from host cells as a primer for transcription (Plotch et al. 1981). The completed RNA transcripts in mammalian cells are frequently processed by a mechanism of RNA splicing, by which a leader RNA from the 5′ end is fused to downstream RNA sequences (Padgett et al. 1986). In this process, segments of intron sequences are removed. This RNA splicing can be mediated either by specific nuclear components (Padgett et al. 1986) or by RNA molecules themselves, such as in the case of Tetrahymena...