Author Archives: azaleaazelia

  RNA sequences regulating transcription The transcription process is controlled by transcription-regulating sequences (TRSs) located at the 3′ end of the leader sequence (TRS-L) and preceding each viral gene (TRS-B). TRSs include a conserved core sequence (CS) 6-7 nt in … Continue reading →

  Moreover, as noted below, the complement of the leader sequence supports initiation of positive-strand RNA synthesis, making the negative-strand subgenomic RNAs (sgRNAs) a template for further amplification of positive-strand sgmRNAs.

  The observation raises the question of whether the presence of the leader sequence in coronavirus sgmRNAs provides any selective advantage to the virus. The presence of the 5′ leader sequence was shown to protect SARS-CoV mRNAs from nsp1-induced endonucleolytic … Continue reading →

  The transcription mechanismin coronaviruses is seemingly complicated as compared with the transcription mechanisms in other positive-strand RNA viruses, such as internal initiation and premature termination. In fact, in contrast to coronavirus and arterivirus sgmRNAs, subgenomic transcripts of other Nidovirales, … Continue reading →

  In contrast to replication, coronavirus transcription includes a discontinuous step during the production of sgmRNA. This process, unique among known RNA viruses, is a hallmark of the order Nidovirales and ultimately generates a nested set of sgmRNAs that are … Continue reading →

  Like that of other positive-strand RNA viruses, coronavirus genome replication is a process of continuous synthesis that utilizes a full-length complementary negative-strand RNA as the template for the production of progeny virus genomes. The initiation  of negative-strand synthesis involves … Continue reading →

  Coronavirus RNA-dependent RNA synthesis includes two differentiated processes: genome replication, yielding multiple copies of genomic RNA (gRNA), and transcription of a collection of sgmRNAs that encode the viral structural and accessories proteins.