pfam05902: 4_1_CTD (This model is not part of the current CDD release)
4.1 protein C-terminal domain (CTD)
At the C-terminus of all known 4.1 proteins is a sequence domain unique to these proteins, known as the C-terminal domain (CTD). Mammalian CTDs are associated with a growing number of protein-protein interactions, although such activities have yet to be associated with invertebrate CTDs. Mammalian CTDs are generally defined by sequence alignment as encoded by exons 18-21. Comparison of known vertebrate 4.1 proteins with invertebrate 4.1 proteins indicates that mammalian 4.1 exon 19 represents a vertebrate adaptation that extends the sequence of the CTD with a Ser/Thr-rich sequence. The CTD was first described as a 22/24-kDa domain by chymotryptic digestion of erythrocyte 4.1 (4.1R). CTD is thought to represent an independent folding structure which has gained function since the divergence of vertebrates from invertebrates.
Jiyao W et al.(2023). "The conserved domain database in 2023.",