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Molecular dynamics simulations on apo ADP/ATP carrier shed new lights on the featured motif of the mitochondrial carriers.

Authors :
Yi Q
Li Q
Yao S
Chen Y
Guan MX
Cang X
Source :
Mitochondrion [Mitochondrion] 2019 Jul; Vol. 47, pp. 94-102. Date of Electronic Publication: 2019 May 23.
Publication Year :
2019

Abstract

The ADP/ATP carrier (AAC) is a transporter responsible for the equal molar exchange of cytosolic ADP and ATP synthesized within mitochondrial matrix across the mitochondrial membrane. Its primary structure consists of three homologous repeats, and each repeat contains a conserved motif that is shared by all members of the mitochondrial carrier family (MCF). Although these MCF motif residues cluster together in the crystal structure of AAC, detailed analyses on the interactions among the motif residues are still limited. In the present study, all-atom molecular dynamics (MD) simulations of up to 10 μs have been carried out on AAC, and interactions and structural dynamics of the MCF motif residues have been specifically investigated. Our simulations have revealed: i) a very asymmetrical electrostatic network at the bottom of the pocket of apo AAC, ii) the asymmetrical interactions between the Pro kink region and the [YWF][KR] G motif in three repeats, iii) the role of the conserved Arg residues in stabilizing the C-ends of the odd-numbered helices, iv) the structural change of the [YWF][KR] G motif and its potential involvement in substrate translocation process. Our results highlight the asymmetry of the MCF residues in the three repeats, which might contribute to the ability of the carriers to transport the asymmetrical substrates. Our observations provide microscopic basis for further research on the translocation mechanism of mitochondrial carriers.<br /> (Copyright © 2019 Elsevier B.V. and Mitochondria Research Society. All rights reserved.)

Details

Language :
English
ISSN :
1872-8278
Volume :
47
Database :
MEDLINE
Journal :
Mitochondrion
Publication Type :
Academic Journal
Accession number :
31129042
Full Text :
https://doi.org/10.1016/j.mito.2019.05.006