RNA Polymerase II Associated Factor 1 (PAF1)

PAF1 is a subunit of the PAF protein complex by analysis of proteins that coimmunoprecipitated with parafibromin from the 293T human embryonic kidney cell line. The immunoprecipitate also contained POLR2A that was unphosphorylated, phosphorylated on ser5, or phosphorylated on ser2, suggesting that the PAF complex may be involved in both initiation and elongation.The deduced protein has a calculated molecular mass of 59.9 kD and contains 3 N-terminal MYC-type helix-loop-helix domains, followed by a leucine zipper, a central DEAD-box subfamily ATP-dependent helicase domain, an RNA recognition motif, and a C-terminal regulator of chromosome condensation (RCC1) signature. Toward the C terminus are also a glutamine-rich domain and a serine- and aspartic acid-rich domain.