P24928

RNA polymerase II (RNAPII) is a large multi-protein complex that functions as a DNA-dependent RNA polymerase, catalyzing the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. The largest subunit, Rpb1 (RNAPII subunit B1) also known as RNAPII subunit A (POLR2A), Rpb1 CTD being a 1840 amino acid protein featuring a C2H2-type zinc finger and a C-terminal domain rich in heptapeptide repeats. Rpb1 is essential for RNA Polymerase II′s catalytic activity and forms the active center responsible for synthesizing messenger RNA. Rpb1 also contributes to RNA Polymerase II′s DNA-binding domain, creating a groove necessary for accurate DNA template transcription. Rpb1 dysfunction can severely impair mRNA synthesis and hinder transcription elongation, underscoring RNA Polymerase II′s importance in cellular function and gene regulation.