Subgenomic RNA synthesis directed by a synthetic defective interfering RNA of mouse hepatitis virus: a study of coronavirus transcription initiation.
AUTOR(ES)
van der Most, R G
RESUMO
We have used a full-length cDNA clone of a mouse hepatitis virus strain A59 defective interfering (DI) RNA, pMIDI-C, and cassette mutagenesis to study the mechanism of coronavirus subgenomic mRNA synthesis. Promoter sequences closely resembling those of subgenomic mRNAs 3 and 7 were inserted into MIDI-C. Both subgenomic RNA promoters gave rise to the synthesis of a subgenomic DI RNA in virus-infected and DI RNA-transfected cells. From a mutagenic analysis of the promoters we concluded the following. (i) The extent of base pairing between the leader RNA and the intergenic promoter sequence does not control subgenomic RNA abundance. (ii) Promoter recognition does not rely on base pairing only. Presumably, transcription initiation requires recognition of the promoter sequence by the transcriptase. (iii) Fusion of leader and body sequences takes place at multiple--possibly random--sites within the intergenic promoter sequence. A model is presented in which, prior to elongation, the leader RNA is trimmed by a processive 3'-->5' nuclease.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=236870Documentos Relacionados
- Coronavirus transcription: subgenomic mouse hepatitis virus replicative intermediates function in RNA synthesis.
- A system for study of coronavirus mRNA synthesis: a regulated, expressed subgenomic defective interfering RNA results from intergenic site insertion.
- A subgenomic mRNA transcript of the coronavirus mouse hepatitis virus strain A59 defective interfering (DI) RNA is packaged when it contains the DI packaging signal.
- The 3' untranslated region of coronavirus RNA is required for subgenomic mRNA transcription from a defective interfering RNA.
- The Leader RNA of Coronavirus Mouse Hepatitis Virus Contains an Enhancer-Like Element for Subgenomic mRNA Transcription