Figure 4. The HECT‐type E3 ligase Smurf1 in Ub coat formation of cytosolic Mycobacterium .

Domain schematic of Smurf1 highlighting the C2 domain required for bacterial binding (red dotted box) and C‐terminal HECT domain with E3 ligase activity. In its apo state, Smurf1 forms inactive homodimers. Interaction between the C2 domain and cytosolic Mycobacterium might relieve Smurf1’s autoinhibition and trigger K48‐linked Ub chain synthesis. Autophagy adaptor protein NBR1 recruits phagophores and initiates xenophagy.