The carboxy?terminal domain of the largest subunit of the RNA polymerase II (CTD) is comprised of multiple repeats of a conserved heptapeptide with the consensus sequence-Tyr-Ser-Pro-Thr-Ser-Pro-Ser-.

• RNA聚合酶II最大亚基末端的羧基端结构域(CTD)是由以七氨基酸(%24CTyr-Ser-Pro-Thr-Ser-Pro-Ser-)为重复单位的高度保守的重复序列组成的。