5H54

Mdm12 from K. lactis 1-239

Summary for 5H54

• Entry DOI: 10.2210/pdb5h54/pdb
• Related: 5H55 5H5A 5H5C
• Descriptor: Mitochondrial distribution and morphology protein 12 (1 entity in total)
• Functional Keywords: lipid binding protein
• Biological source: Kluyveromyces lactis (strain ATCC 8585 / CBS 2359 / DSM 70799 / NBRC 1267 / NRRL Y-1140 / WM37) (Yeast)
• Cellular location: Mitochondrion outer membrane ; Peripheral membrane protein ; Cytoplasmic side : Q6CUC3
• Total number of polymer chains: 1
• Total formula weight: 29499.64

Authors

Kawano, S.,Quinbara, S.,Endo, T. (deposition date: 2016-11-04, release date: 2017-11-08, Last modification date: 2024-03-20)

Primary citation

Kawano, S.,Tamura, Y.,Kojima, R.,Bala, S.,Asai, E.,Michel, A.H.,Kornmann, B.,Riezman, I.,Riezman, H.,Sakae, Y.,Okamoto, Y.,Endo, T.
Structure-function insights into direct lipid transfer between membranes by Mmm1-Mdm12 of ERMES
J. Cell Biol., 217:959-974, 2018

PubMed Abstract: The endoplasmic reticulum (ER)-mitochondrial encounter structure (ERMES) physically links the membranes of the ER and mitochondria in yeast. Although the ER and mitochondria cooperate to synthesize glycerophospholipids, whether ERMES directly facilitates the lipid exchange between the two organelles remains controversial. Here, we compared the x-ray structures of an ERMES subunit Mdm12 from with that of Mdm12 from and found that both Mdm12 proteins possess a hydrophobic pocket for phospholipid binding. However in vitro lipid transfer assays showed that Mdm12 alone or an Mmm1 (another ERMES subunit) fusion protein exhibited only a weak lipid transfer activity between liposomes. In contrast, Mdm12 in a complex with Mmm1 mediated efficient lipid transfer between liposomes. Mutations in Mmm1 or Mdm12 impaired the lipid transfer activities of the Mdm12-Mmm1 complex and furthermore caused defective phosphatidylserine transport from the ER to mitochondrial membranes via ERMES in vitro. Therefore, the Mmm1-Mdm12 complex functions as a minimal unit that mediates lipid transfer between membranes.

PubMed: 29279306
DOI: 10.1083/jcb.201704119

Experimental method

X-RAY DIFFRACTION (3.1 Å)