Proto-mitochondrion

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Proto-mitochondrion
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Alpha Proteobacteria

The proto-mitochondrion is the ancestral bacterial endosymbiont from which all mitochondria are thought to be derived.

Phylogeny[edit]

The phylogenetic analyses of the few genes that are still encoded in the genomes of modern mitochondria suggest an alpha-proteobacterial origin for this endosymbiont. Although the order Rickettsiales has been proposed as the alpha-proteobacterial sister-group of mitochondria, there is no definitive evidence as to from which alpha-proteobacterial group the proto-mitochondrion emerged.

Phylogeny of Rickettsiales
Other alphaproteobacteria

Rhodospirillales, Sphingomonadales, Rhodobacteraceae, Rhizobiales, etc.


Rickettsiales
SAR11 clade

Pelagibacter ubique




Mitochondria



Anaplasmataceae



Ehrlichia



Anaplasma




Wolbachia




Neorickettsia



Rickettsiaceae

Rickettsia






Robust phylogeny of Rickettsiales from Williams et al. (2007)[1]


Metabolism[edit]

Toni Gabaldón and Martijn Huynen (2003) reconstructed the proteome (the entire set of proteins expressed by a genome) and corresponding metabolism of the proto-mitochondrion by comparing extant alpha-proteobacterial and eukaryotic genomes. They concluded that this organism was an aerobic alpha-proteobacterium catabolyzing lipids, glycerol and other compounds provided by the host. At least 630 gene families derived from this organism can still be found in the 9 eukaryotic genomes analyzed in the study.[2]

See also[edit]

References[edit]

  1. ^ Williams, K. P.; Sobral, B. W.; Dickerman, A. W. (2007). "A Robust Species Tree for the Alphaproteobacteria". Journal of Bacteriology 189 (13): 4578–4586. doi:10.1128/JB.00269-07. PMC 1913456. PMID 17483224.  edit
  2. ^ Gabaldón, T.; et al. (2003). "The proto-mitochondrial metabolism". Science 301 (5633): 690. doi:10.1126/science.1085463. PMID 12893934.