RNA-directed RNA polymerase L protein (Zaire ebolavirus) (L protein)

The RNA-directed RNA polymerase L protein is the largest and catalytically essential subunit of the viral polymerase complex of Zaire ebolavirus (EBOV). L, along with its obligate cofactor Viral Protein 35 (VP35), forms the core enzymatic unit that drives viral RNA synthesis, including both genome replication and mRNA transcription, as well as capping and polyadenylation of viral transcripts. The L protein possesses multiple functional domains: the RNA-dependent RNA polymerase, capping (PRNTase), connector, methyltransferase, and a small C-terminal domain. The L–VP35 complex is validated as a promising broad-spectrum antiviral target, with suramin and other compounds shown to inhibit its activity by blocking nucleotide access to the active site. Disruption or mutation of L protein can significantly impair or abrogate the virus's ability to propagate, making it crucial for the Ebola virus life cycle. No approved drugs yet specifically target L in clinical use, but it is a major focus in the search for new filovirus therapeutics.

Other names

L polymeraseL proteinRNA polymerase LLarge protein (L)RNA-dependent RNA polymerase (RdRp L)EBOV LZaire ebolavirus L

Polymerase inhibition: Drugs (e.g., suramin) block the NTP (nucleotide triphosphate) entry channel in the polymerase complex, preventing RNA synthesis and viral replication.