9.A.58 The Maintenance of Mitochondrial Morphology (MMM) Family 

The MMM proteins are components of ERMES/MDM complexes, which serve as a molecular tethers to interconnect the endoplasmic reticulum and mitochondria. Components of this complex are involved in the control of mitochondrial shape and protein biogenesis and may function in phospholipid exchange. The MDM12-MMM1 subcomplex functions in the major beta-barrel assembly pathway that is responsible for biogenesis of all outer membrane beta-barrel proteins, and acts in a late step after the SAM complex. The MDM10-MDM12-MMM1 subcomplex further acts in the TOM40-specific pathway after the action of the MDM12-MMM1 complex. These complexes are essential for establishing and maintaining the structure of mitochondria and for the maintenance of mtDNA nucleoids (Burgess et al. 1994; Boldogh et al. 1998; Hobbs et al. 2001; Meisinger et al. 2007).  These proteins are believed to be members of the TULIP superfamily (see also TC# 1.C.40 and 9.A.57) (Alva and Lupas 2016).