| Primary Identifier | IPR041641 | Type | Domain |
| Short Name | CALCOCO1/2_Zn_UBZ1 |
| description | The ubiquitin-binding zinc finger (UBZ) is a type of zinc-coordinating β-β-α fold domain found mainly in proteins involved in DNA repair and transcriptional regulation. UBZ domains coordinate a zinc ion with cysteine or histidine residues; depending on their amino acid sequence, UBZ domains are classified into several families [, ]. Type 1 UBZs are CCHH-type zinc fingers found in tandem UBZ domains of TAX1-binding protein 1 (TAX1BP1) [, , ], type 2 UBZs are CCHC-type zinc fingers found in FAAP20 which is a subunit of the Fanconi anemia (FA) core complex [, ], type 3 UBZs are CCHH-type zinc fingers found only in the Y-family translesion polymerase eta [, , ], and type 4UBZs are CCHC-type zinc fingers found in Y-family translesion polymerase kappa, Werner helicase-interacting protein 1 (WRNIP1), and Rad18 [, , ]. The UBZ domain consists of two short antiparallel β-strands followed by one α-helix. The α-helix packs against the β-strands with a zinc ion sandwiched between the α-helix and the β-strands. The zinc ion is coordinated by two cysteines located on the fingertip formed by the β-strands and two histidines [, ]or one histidine and one cysteine []on the α-helix [].This entry represents the UBZ1 type zinc finger domain found in calcium-binding and coiled-coil domain 1/2 (CALCOCO1/2), tax-binding protein 1 and protein spindle-F.This domain is a typical C2H2-type zinc finger which specifically recognizes mono-ubiquitin or poly-ubiquitin chain. The overall ubiquitin-binding mode utilizes the C-terminal α-helix to interact with the solvent-exposed surface of the central β-sheet of ubiquitin, similar to that observed in the RABGEF1/Rabex-5 or POLN/Pol-eta zinc finger [].CALCOCO2 (also known as NDP25) is an ubiquitin-binding autophagy receptor involved in the selective autophagic degradation of invading pathogens []. Tax binding protein 1 is a ubiquitin binding protein []and protein spindle-F plays a role in oocyte axis determination and microtubule organization during oogenesis in Drosophila [, ]. |
