4XHR

Structure of a phospholipid trafficking complex, native

Summary for 4XHR

• Entry DOI: 10.2210/pdb4xhr/pdb
• Related: 4XIZ
• Descriptor: Protein UPS1, mitochondrial, Mitochondrial distribution and morphology protein 35 (3 entities in total)
• Functional Keywords: phospholipid, lipid transport-oxidoreductase complex, lipid transport/oxidoreductase
• Biological source: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast); More
• Cellular location: Mitochondrion inner membrane; Peripheral membrane protein; Intermembrane side: Q05776; Cytoplasm: O60200
• Total number of polymer chains: 4
• Total formula weight: 62959.25

Authors

Yu, F.,He, F.,Wang, C.,Zhang, P. (deposition date: 2015-01-06, release date: 2015-07-01, Last modification date: 2015-08-05)

Primary citation

Yu, F.,He, F.,Yao, H.,Wang, C.,Wang, J.,Li, J.,Qi, X.,Xue, H.,Ding, J.,Zhang, P.
Structural basis of intramitochondrial phosphatidic acid transport mediated by Ups1-Mdm35 complex
Embo Rep., 16:813-823, 2015

PubMed Abstract: Ups1 forms a complex with Mdm35 and is critical for the transport of phosphatidic acid (PA) from the mitochondrial outer membrane to the inner membrane. We report the crystal structure of the Ups1-Mdm35-PA complex and the functional characterization of Ups1-Mdm35 in PA binding and transfer. Ups1 features a barrel-like structure consisting of an antiparallel β-sheet and three α-helices. Mdm35 adopts a three-helical clamp-like structure to wrap around Ups1 to form a stable complex. The β-sheet and α-helices of Ups1 form a long tunnel-like pocket to accommodate the substrate PA, and a short helix α2 acts as a lid to cover the pocket. The hydrophobic residues lining the pocket and helix α2 are critical for PA binding and transfer. In addition, a hydrophilic patch on the surface of Ups1 near the PA phosphate-binding site also plays an important role in the function of Ups1-Mdm35. Our study reveals the molecular basis of the function of Ups1-Mdm35 and sheds new light on the mechanism of intramitochondrial phospholipid transport by the MSF1/PRELI family proteins.

PubMed: 26071601
DOI: 10.15252/embr.201540137

Experimental method

X-RAY DIFFRACTION (2.55 Å)