RNA Polymerase II, DNA Directed Polypeptide D (POLR2D)

The DNA-dependent RNA polymerase II (EC 2.7.7.6) is responsible for the transcription of protein-encoding genes. It is composed of 10 to 14 subunits ranging in mass from approximately 220 kD (POLR2A) to approximately 7 kD (POLR2K).

The full-length POLR2D cDNA encodes a 142-amino acid protein with a calculated molecular mass of 16.3 kD. The protein shares 98% sequence identity with its mouse homolog. Northern blot analysis detected 2- and 5.5-kb POLR2D transcripts in all tissues tested, with highest levels in skeletal muscle and heart. Immunofluorescence studies demonstrated that POLR2D is localized in the nucleus.POLR2D associates strongly and specifically with POLR2G when expressed in yeast or in mammalian cells and copurifies with intact pol II.