C-terminal deadenylase domain of CCR4b, also known as CCR4-NOT transcription complex subunit 6-like
This subfamily contains the C-terminal catalytic domain of the deadenylase, CCR4b, also known as CCR4-NOT transcription complex subunit 6-like (CNOT6L). 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. CCR4 is the major deadenylase subunit of the CCR4-NOT transcription complex, which contains two deadenylase subunits and several noncatalytic subunits. The other deadenylase subunit, Caf1, is a DEDD-type protein and does not belong in this superfamily. There are two vertebrate CCR4 proteins, CCR4a (also called CCR4-NOT transcription complex subunit 6 or CNOT6) and CCR4b. CCR4b associates with other components, such as CNOT1-3 and Caf1, to form a CCR4-NOT multisubunit complex, which regulates transcription and mRNA degradation. The nuclease domain of CCR4b exhibits Mg2+-dependent deadenylase activity with strict specificity for poly (A) RNA as substrate. CCR4b is mainly localized in the cytoplasm. It regulates cell growth and influences cell cycle progression by regulating p27/Kip1 mRNA levels. It contributes to the prevention of cell death by regulating insulin-like growth factor-binding protein 5.
Jiyao W et al.(2023). "The conserved domain database in 2023.",