Biology Faculty Articles
Document Type
Article
Publication Date
3-2008
Publication Title
BMC Genomics
ISSN
1471-2164
Volume
9
Issue/No.
119
First Page
1
Last Page
22
Abstract
Background
The mitochondria produce up to 95% of a eukaryotic cell's energy through oxidative phosphorylation. The proteins involved in this vital process are under high functional constraints. However, metabolic requirements vary across species, potentially modifying selective pressures. We evaluate the adaptive evolution of 12 protein-coding mitochondrial genes in 41 placental mammalian species by assessing amino acid sequence variation and exploring the functional implications of observed variation in secondary and tertiary protein structures.
Results
Wide variation in the properties of amino acids were observed at functionally important regions of cytochrome b in species with more-specialized metabolic requirements (such as adaptation to low energy diet or large body size, such as in elephant, dugong, sloth, and pangolin, and adaptation to unusual oxygen requirements, for example diving in cetaceans, flying in bats, and living at high altitudes in alpacas). Signatures of adaptive variation in the NADH dehydrogenase complex were restricted to the loop regions of the transmembrane units which likely function as protons pumps. Evidence of adaptive variation in the cytochrome c oxidase complex was observed mostly at the interface between the mitochondrial and nuclear-encoded subunits, perhaps evidence of co-evolution. The ATP8 subunit, which has an important role in the assembly of F0, exhibited the highest signal of adaptive variation. ATP6, which has an essential role in rotor performance, showed a high adaptive variation in predicted loop areas.
Conclusion
Our study provides insight into the adaptive evolution of the mtDNA genome in mammals and its implications for the molecular mechanism of oxidative phosphorylation. We present a framework for future experimental characterization of the impact of specific mutations in the function, physiology, and interactions of the mtDNA encoded proteins involved in oxidative phosphorylation.
Additional Comments
Portuguese Foundation for Science and Technology grant #s: POCTI/BSE/47559/2002, PTDC/BIA-BDE/69144/2006; National Geographic Society grant #: 7483-03; National Cancer Institute contract #: N01-CO-12400
NSUWorks Citation
da Fonseca, Rute R.; Warren E. Johnson; Stephen J. O'Brien; Maria J. Ramos; and Agostinho Antunes. 2008. "The Adaptive Evolution of the Mammalian Mitochondrial Genome." BMC Genomics 9, (119): 1-22. https://nsuworks.nova.edu/cnso_bio_facarticles/772
ORCID ID
0000-0001-7353-8301
ResearcherID
N-1726-2015
Comments
© 2008 da Fonseca et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.