Phylogenomic Reconstruction Indicates Mitochondrial Ancestor Was an Energy Parasite
Zhang Wang, Martin Wu mail
Published: October 15, 2014DOI: 10.1371/journal.pone.0110685
Abstract
Reconstruction of mitochondrial ancestor has great impact on our understanding of the origin of mitochondria. Previous studies have largely focused on reconstructing the last common ancestor of all contemporary mitochondria (proto-mitochondria), but not on the more informative pre-mitochondria (the last common ancestor of mitochondria and their alphaproteobacterial sister clade). Using a phylogenomic approach and leveraging on the increased taxonomic sampling of alphaproteobacterial and eukaryotic genomes, we reconstructed the metabolisms of both proto-mitochondria and pre-mitochondria. Our reconstruction depicts a more streamlined proto-mitochondrion than these predicted by previous studies, and revealed several novel insights into the mitochondria-derived eukaryotic metabolisms including the lipid metabolism. Most strikingly, pre-mitochondrion was predicted to possess a plastid/parasite type of ATP/ADP translocase that imports ATP from the host, which posits pre-mitochondrion as an energy parasite that directly contrasts with the current role of mitochondria as the cell’s energy producer. In addition, pre-mitochondrion was predicted to encode a large number of flagellar genes and several cytochrome oxidases functioning under low oxygen level, strongly supporting the previous finding that the mitochondrial ancestor was likely motile and capable of oxidative phosphorylation under microoxic condition.
Citation: Wang Z, Wu M (2014) Phylogenomic Reconstruction Indicates Mitochondrial Ancestor Was an Energy Parasite. PLoS ONE 9(10): e110685. doi:10.1371/journal.pone.0110685
Editor: Frank Voncken, University of Hull, United Kingdom
Received: July 14, 2014; Accepted: September 22, 2014; Published: October 15, 2014
Copyright: © 2014 Wang, Wu. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper and its Supporting Information files. The genome sequences have been deposited at DDBJ/EMBL/GenBank as follows: endosymbiont of acanthamoeba UWC8 (CP004403), Candidatus Caedibacter acanthamoebae (CP008936-CP008940), Candidatus Paracaedibacter acanthamoebae (CP008941-CP008942), Candidatus Paracaedibacter symbiosus (JQAK00000000) and NHP bacterium (JQAJ00000000).
Funding: This research was funded by an award from Thomas F. & Kate Miller Jeffress Memorial Trust to MW. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
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