Respiratory Syncytial Virus Transcription Elongation Factor M2-1 (M2-1)

The M2-1 protein is a critical transcription elongation and antitermination factor encoded by the respiratory syncytial virus (RSV). It is essential for efficient synthesis of full-length viral mRNAs and polycistronic readthrough mRNAs. M2-1 acts as both a transcriptional processivity factor and an antiterminator, preventing premature termination during viral mRNA synthesis. It also enables the RNA-dependent RNA polymerase (RdRp) to transcribe through gene end signals. The protein forms tetramers that interact competitively with both RNA and the phosphoprotein (P) and contains an N-terminal CCCH-type zinc finger motif essential for its function.

Other names

Envelope-associated 22 kDa proteinTranscription antitermination factor M2–1Vp24

Inhibition of transcription elongation and antitermination