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
Magnetococcidae
Magnetococcales
Magnetococcaceae

Magnetococcus marinus





Caulobacteridae

Rhodospirillales, Sphingomonadales, Rhodobacteraceae, Rhizobiales, etc.



Holosporales



Rickettsidae
Pelagibacterales
Pelagibacteraceae

Pelagibacter




subgroups Ib, II, IIIa, IIIb, IV and V





Mitochondria



Anaplasmataceae



Ehrlichia



Anaplasma




Wolbachia




Neorickettsia




Midichloriaceae

Midichloria



Rickettsiaceae

Rickettsia








Robust 16S + 23S phylogeny of Rickettsidae from Ferla et al. (2013)[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. ^ Ferla, M. P.; Thrash, J. C.; Giovannoni, S. J.; Patrick, W. M. (2013). "New rRNA gene-based phylogenies of the Alphaproteobacteria provide perspective on major groups, mitochondrial ancestry and phylogenetic instability". PLoS ONE 8 (12): e83383. doi:10.1371/journal.pone.0083383. PMC 3859672. PMID 24349502.  edit
  2. ^ Gabaldón, T. et al. (2003). "The proto-mitochondrial metabolism". Science 301 (5633): 690. doi:10.1126/science.1085463. PMID 12893934.