The Respiratory Syncytial Virus Polymerase Has Multiple RNA Synthesis Activities at the Promoter

PLoS Pathogens

Laure R. Deflubé¹  Chadene Z. Tremaglio¹  Sarah L. Noton¹  Rachel Fearns¹ 

[1] Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America

关键词: RNA synthesis;    RNA sequence analysis;    RNA structure;    RNA isolation;    Polymerases;    Oligonucleotides;    RNA viruses;    Sequence analysis;   

DOI  :  10.1371/journal.ppat.1002980

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Respiratory syncytial virus (RSV) is an RNA virus in the Family Paramyxoviridae. Here, the activities performed by the RSV polymerase when it encounters the viral antigenomic promoter were examined. RSV RNA synthesis was reconstituted in vitro using recombinant, isolated polymerase and an RNA oligonucleotide template representing nucleotides 1–25 of the trailer complement (TrC) promoter. The RSV polymerase was found to have two RNA synthesis activities, initiating RNA synthesis from the +3 site on the promoter, and adding a specific sequence of nucleotides to the 3′ end of the TrC RNA using a back-priming mechanism. Examination of viral RNA isolated from RSV infected cells identified RNAs initiated at the +3 site on the TrC promoter, in addition to the expected +1 site, and showed that a significant proportion of antigenome RNAs contained specific nucleotide additions at the 3′ end, demonstrating that the observations made in vitro reflected events that occur during RSV infection. Analysis of the impact of the 3′ terminal extension on promoter activity indicated that it can inhibit RNA synthesis initiation. These findings indicate that RSV polymerase-promoter interactions are more complex than previously thought and suggest that there might be sophisticated mechanisms for regulating promoter activity during infection.

【 授权许可】

CC BY