The Ccr4-Not complex is a large assembly involved in the regulation of eukaryotic gene expression at multiple levels. The best-studied function of Ccr4-Not relates to its action as the major deadenylase involved in shortening the poly(A) tail of cellular mRNAs in the cytoplasm PMID:24121231. The conserved core of the CCR4-NOT complex consists of two major modules: a catalytic module comprising two deadenylases (CAF1 or its paralogue POP2, and CCR4a or its paralogue CCR4b) and the NOT module, which minimally consists of NOT1, NOT2 and NOT3 PMID:22027279.

This entry represents the C-terminal domain of subunits 2, 3 and 5 of the complex. The C-terminal regions of NOT2 and NOT3 contain a conserved SH3-like NOT-box domain which mediates NOT-module assembly PMID:24121232.