The elongin (SIII) complex is composed of a transcriptionally active A subunit and two small regulatory subunits, B and C. This complex stimulates the transcription elongation rate of RNA polyermase II by suppressing time spent at template-encoded arresting sites along DNA. Elongin A3, also known as RNA polymerase II transcription factor SIII subunit A3 and Transcription elongation factor B polypeptide 3C, is a 546 amino acid nuclear protein that functions as a general transcription elongation factor that increases RNA polymerase II transcription elongation and forms a stable complex with Elongin BC. In contrast to Elongin A, transcriptional activity of Elongin A3 is not stimulated by Elongin BC. Elongin A3 contains one TFIIS N-terminal domain and is ubiquitously expressed in human tissue.
EloA3; ELOA3A; Elongin-A3; HsT829; RNA polymerase II transcription factor SIII subunit A3; TCEB3C; TCEB3L2; Transcription elongation factor B polypeptide 3C; transcription elongation factor B polypeptide 3C (elongin A3)