pfam00658: MLLE (This model is not part of the current CDD release)
MLLE domain
The MLLE domain, also known as the PABC or CTC domain, is found at the C-terminus of cytoplasmic poly(A)-binding proteins (PABPs). It consists of a bundle of 4-5 alpha helices and contains a conserved KITGMLLE signature motif. The MLLE domain functions as a peptide-binding domain that interacts with PAM2 (PABP-interacting motif 2) sequences found in various PABP regulatory proteins involved in translation and mRNA decay. Key conserved residues in the MLLE domain form binding pockets that accommodate an invariant phenylalanine and other residues in the PAM2 motif. Besides PABPs, the MLLE domain is also found in the E3 ubiquitin ligase UBR5 where it serves as a protein interaction module. In some fungi, Rrm4 RNA-binding proteins contain a binding platform of 2-3 divergent MLLE domains that interact with PAM2-like motifs in the Upa1 protein to mediate attachment of mRNA-protein particles to endosomes for transport and localized translation.
Jiyao W et al.(2023). "The conserved domain database in 2023.",