This entry represents the C-terminal catalytic domain of the deadenylase CCR4a, also known as CCR4-NOT transcription complex subunit 6 (CNOT6). CCR4 belongs to the large EEP (exonuclease/endonuclease/phosphatase) superfamily that contains functionally diverse enzymes that share a common catalytic mechanism of cleaving phosphodiester bonds. In S. cerevisiae, Ccr4 is the major deadenylase subunit of the CCR4-NOT transcription complex, which contains two deadenylase subunits and several noncatalytic subunits [, ].There are two vertebrate CCR4 proteins, CCR4a and CCR4b (also called CNOT6-like or CNOT6L). CCR4a associates with other components, such as CNOT1-3 and Caf1, to form a CCR4-NOT multisubunit complex, which regulates transcription and mRNA degradation []. CCR4a is a component of P-bodies and is necessary for foci formation of various P-body components [, ]. It also plays a role in cellular responses to DNA damage, by regulating Chk2 activity [].
