The region featured in this family is found towards the C-terminus of poly(A)-binding proteins (PABPs). These are eukaryotic proteins that, through their binding of the 3' poly(A) tail on mRNA, have very important roles in the pathways of gene expression. They seem to provide a scaffold on which other proteins can bind and mediate processes such as export, translation and turnover of the transcripts. Moreover, they may act as antagonists to the binding of factors that allow mRNA degradation, regulating mRNA longevity. PABPs are also involved in nuclear transport. PABPs interact with poly(A) tails via RNA-recognition motifs (PF00076) . Note that the PABP C-terminal region is also found in members of the hyperplastic discs protein (HYD) family of ubiquitin ligases that contain HECT domains - these are also included in this family.
The polyadenylate-binding protein (PABP) has a conserved C-terminal domain (PABC), which is also found in the hyperplastic discs protein (HYD) family of ubiquitin ligases that contain HECT domains (INTERPRO) [PUBMED:11287654]. PABP recognises the 3' mRNA poly(A) tail and plays an essential role in eukaryotic translation initiation and mRNA stabilisation/degradation. PABC domains of PABP are peptide-binding domains that mediate PABP homo-oligomerisation and protein-protein interactions. In mammals, the PABC domain of PABP functions to recruit several different translation factors to the mRNA poly(A) tail [PUBMED:11940585].