Elongin complex is a transcription elongation factor that increases RNA polymerase II elongation rate by suppressing transient pausing. Elongin complex is a heterotrimer composed of the large transcriptionally active subunit elongin A and two regulatory subunits elongin B and C, which form a stable subcomplex that binds to subunit A. (Adapted from
FBrf0223250 and
FBrf0180540).