Proto-mitochondrion
Encyclopedia
The proto-mitochondrion is the ancestral bacterial endosymbiont
from which all mitochondria
are thought to be derived.
l origin for this endosymbiont
. Although the order Rickettsiales
has been proposed as the alpha-proteobacteria
l sister-group of mitochondria, there is no definitive evidence as to from which alpha-proteobacteria
l group the proto-mitochondrion emerged.
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 genome
s analyzed in the study.
Endosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
from which all mitochondria
are thought to be derived.
Phylogeny
The phylogenetic analyses of the few genes that are still encoded in the genomes of modern mitochondria suggest an alpha-proteobacteriaProteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
l origin for this endosymbiont
Endosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
. Although the order Rickettsiales
Rickettsiales
The Rickettsiales, also called rickettsias, are an order of small proteobacteria. Most of those described survive only as endosymbionts of other cells. Some are notable pathogens, including Rickettsia, which causes a variety of diseases in humans...
has been proposed as the alpha-proteobacteria
Proteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
l sister-group of mitochondria, there is no definitive evidence as to from which alpha-proteobacteria
Proteobacteria
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera....
l group the proto-mitochondrion emerged.
Metabolism
Toni Gabaldón and Martijn Huynen (2003) reconstructed the proteome and corresponding metabolism of the proto-mitochondrion by comparing extant alpha-proteobacterial and eukaryotic genomes. They concluded that this organism was an aerobicAerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
alpha-proteobacterium catabolyzing lipids, glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
and other compounds provided by the host. At least 630 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
families derived from this organism can still be found in the 9 eukaryotic genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
s analyzed in the study.