Figure 9.

TDP2 does not have the MGF motif in loop1, conserved in other UBAs. (A) MSA of UBA domains from 17 different UBA-containing proteins. All these UBAs have been structurally characterized and their corresponding PDB IDs are listed on the right. MGF motif in loop 1 and important residues for Ub interaction in helix 3 are highlighted. CeTDP2, lacking the MGF motif, is boxed in red. The only other protein with significant dissimilarity in the MGF motif, mouse RSGI RUH, is boxed in black. Secondary structure schematic on top is representative of the four-helix bundle present in CeTDP2 UBA structure. (B) The 4th helix of TDP2 UBA may provide an extended surface for Ub binding. Hydrophobic residues forming and adjoining the ITA patch in TDP2 UBA (left) and MGF patch as well as hydrophobic residues on helix 3 in Ede1 UBA (right) are highlighted in red and labeled. α-helices are numbered for both structures.