Plays a role in mitochondrial and peroxisomal fission. Promotes the recruitment and association of the fission mediator dynamin-related protein 1 (DNM1L) to the mitochondrial surface. May be involved in regulation of synaptic vesicle membrane dynamics by recruitment of DNM1L to clathrin-containing vesicles. Homodimer. Interacts with DNM1L. Interacts with C11orf65/MFI; the interaction inhibits MFF interaction with DNM1L. Belongs to the Tango11 family.