InterPro domain: IPR005375

This entry represents Ufm1 (ubiquitin-fold modifier), which is a ubiquitin-like protein with structural similarities to ubiquitin [ 1 , 2 ]. Ufm1 is one of a number of ubiquitin-like modifiers that conjugate to target proteins in cells through Uba5 (E1) and Ufc1 (E2). The Ufm1-system is conserved in metazoa and plants, suggesting it has a potential role in multicellular organisms [ 3 ]. Human Ufm1 is synthesized as a precursor consisting of 85 amino-acid residues. Prior to activation by Uba5, the extra amino acids at the C-terminal region of Ufm1 are removed to expose Gly, which is necessary for conjugation to target molecule(s). C-terminal processing of Ufm1 requires two specific cysteine peptidases ( IPR012462 ): UfSP1 and UfSP2; both peptidases are also able to release Ufm1 from Ufm1-conjugated cellular proteins. UfSP2 is present in most, if not all, of multi-cellular organisms including plant, nematode, fly, and mammal, whereas UfSP1 is not present in plants and nematodes [ 4 ].

1. Ubiquitin and its kin: how close are the family ties? Trends Cell Biol. 10, 335-42
2. A novel protein-conjugating system for Ufm1, a ubiquitin-fold modifier. EMBO J. 23, 1977-86
3. Solution structure and dynamics of Ufm1, a ubiquitin-fold modifier 1. Biochem. Biophys. Res. Commun. 343, 21-6
4. Two novel ubiquitin-fold modifier 1 (Ufm1)-specific proteases, UfSP1 and UfSP2. J. Biol. Chem. 282, 5256-62