3A3C

Crystal structure of TIM40/MIA40 fusing MBP, C296S and C298S mutant

Summary for 3A3C

• Entry DOI: 10.2210/pdb3a3c/pdb
• Related: 2K3J 2ZXT
• Related PRD ID: PRD_900001
• Descriptor: Maltose-binding periplasmic protein, LINKER, Mitochondrial intermembrane space import and assembly protein 40, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: mitochondrion, inner membrane space, membrane, disulfide bond transfer, alpha helices, sugar transport, transport, mitochondrion inner membrane, phosphoprotein, protein transport, signal-anchor, transit peptide, translocation, transmembrane
• Biological source: Escherichia coli (strain K12); More
• Cellular location: Mitochondrion inner membrane ; Single- pass type II membrane protein ; Intermembrane side : P36046
• Total number of polymer chains: 1
• Total formula weight: 50056.10

Authors

Kawano, S.,Naoe, M.,Momose, T.,Watanabe, N.,Endo, T. (deposition date: 2009-06-11, release date: 2009-08-04, Last modification date: 2024-10-30)

Primary citation

Kawano, S.,Yamano, K.,Naoe, M.,Momose, T.,Terao, K.,Nishikawa, S.,Watanabe, N.,Endo, T.
Structural basis of yeast Tim40/Mia40 as an oxidative translocator in the mitochondrial intermembrane space.
Proc.Natl.Acad.Sci.USA, 106:14403-14407, 2009

PubMed Abstract: The mitochondrial intermembrane space (IMS) contains many small cysteine-bearing proteins, and their passage across the outer membrane and subsequent folding require recognition and disulfide bond transfer by an oxidative translocator Tim40/Mia40 in the inner membrane facing the IMS. Here we determined the crystal structure of the core domain of yeast Mia40 (Mia40C4) as a fusion protein with maltose-binding protein at a resolution of 3 A. The overall structure of Mia40C4 is a fruit-dish-like shape with a hydrophobic concave region, which accommodates a linker segment of the fusion protein in a helical conformation, likely mimicking a bound substrate. Replacement of the hydrophobic residues in this region resulted in growth defects and impaired assembly of a substrate protein. The Cys296-Cys298 disulfide bond is close to the hydrophobic concave region or possible substrate-binding site, so that it can mediate disulfide bond transfer to substrate proteins. These results are consistent with the growth phenotypes of Mia40 mutant cells containing Ser replacement of the conserved cysteine residues.

PubMed: 19667201
DOI: 10.1073/pnas.0901793106

Experimental method

X-RAY DIFFRACTION (2.5 Å)