(a) Scheme of the S. cerevisiae Not4 protein. The different domains are indicated (RING: ring domain, CC: coiled coil, RRM, putative RNA recognition motif, C3H1 zinc finger, and Ccr4-Not interaction domain) [82]. (b) Scheme of the S. cerevisiae Ccr4-Not complex. The Ccr4-Not complex contains the 9 indicated proteins. Not2, Not4, and Not5 were mapped to the C-terminus of the Not1 scaffold by 2-hybrid experiments [83, 84], while a recent structure of Ccr4, Caf1, and Not1 confirmed the previous mapping to a central portion of Not1 [85]. The last 3 proteins have not been precisely positioned with regard to the scaffold.