Fig. 6: Replication of the RNA Genome and Transcription of Viral mRNAs

Genome replication.
RNA-dependant RNA polymerase copies the entire (+) sense RNA genome as a complementary (-) antisense RNA (3' to 5'). It then copies the entire (-) antisense RNA as complementary (+) sense RNA genomes (3' to 5'). See arrows. Also see Fig. 4.

Transcription of the various viral mRNAs coding for viral proteins.
RNA polymerase copies a portion of the (+) sense RNA genome until it comes to one of the transcription regulatory sequences (TRS) along the molecule, at which time it jumps all the way to the leaderTRS at the 5' end, thus generating various short subgenomic (-) antisense RNAs of varying length. RNA polymerase then transcribes these subgenomic (-) antisense RNAs to (+) sense mRNAs coding for the various viral structural proteins and enzymes.

Illustration of the Replication of the RNA Genome and Transcription of Viral mRNAs .jpg by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at https://cwoer.ccbcmd.edu/science/microbiology/index_gos.html.

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Last updated: Feb., 2021
Please send comments and inquiries to Dr. Gary Kaiser