| Domain name | InterPro ID | Approximate residue positions in mammalian Hip/ST13 | Known function |
|---|---|---:|---|
| Hip_N | IPR034649 | 1–44 | N-terminal dimerization domain; forms a stable Hip dimer that supports avid Hsp70 binding and co-chaperone function (pqac-00000011, pqac-00000012) |
| STI1_HS-bd | IPR006636 | ~113–214 | TPR-containing Hsp70-binding module; binds the Hsp70 nucleotide-binding/ATPase domain preferentially in the ADP-bound state and stabilizes Hsp70-substrate complexes by slowing ADP release (pqac-00000011, pqac-00000013, pqac-00000015) |
| TPR repeat | IPR019734 | within ~113–214 | Repeated tetratricopeptide motifs that build the Hsp70-binding scaffold; mediate protein–protein interaction with Hsp70 and contribute to attenuation of the Hsp70 chaperone cycle (pqac-00000012, pqac-00000013) |
| TPR-like helical domain superfamily | IPR011990 | within ~113–214 | Helical superstructure underlying the TPR region; provides the structural scaffold for docking onto Hsp70’s nucleotide-binding domain and forming the “bracket” that stabilizes the ADP-bound conformation (pqac-00000013, pqac-00000031) |
| GGMP repeat region | — | ~278–311 | Flexible repeat-rich region with seven imperfect GGMP tetrapeptide repeats; precise role remains unresolved, but it is part of the conserved C-terminal region associated with Hip function in substrate/chaperone complexes (pqac-00000012, pqac-00000017) |
| STI1/HOP_DP | IPR041243 | ~312–368 | C-terminal DP domain; contains hydrophobic grooves implicated in binding non-native substrate segments and is important for substrate/client handling and conformational maturation in vivo (pqac-00000011, pqac-00000012, pqac-00000013) |


*Table: This table summarizes the conserved domain architecture of C. elegans HIP-1/T12D8.8 inferred from UniProt domain calls and mechanistic studies of mammalian Hip/ST13. It is useful for mapping sequence features to likely co-chaperone functions in Hsp70-dependent proteostasis.*