TY - JOUR

T1 - Alpha proteobacterial ancestry of the [Fe-Fe]-hydrogenases in anaerobic eukaryotes

AU - Degli Esposti, Mauro

AU - Cortez, Diego

AU - Lozano, Luis

AU - Rasmussen, Simon

AU - Nielsen, Henrik Bjørn

AU - Martinez Romero, Esperanza

PY - 2016/7/30

Y1 - 2016/7/30

N2 - UNLABELLED: Eukaryogenesis, a major transition in evolution of life, originated from the symbiogenic fusion of an archaea with a metabolically versatile bacterium. By general consensus, the latter organism belonged to α proteobacteria, subsequently evolving into the mitochondrial organelle of our cells. The consensus is based upon genetic and metabolic similarities between mitochondria and aerobic α proteobacteria but fails to explain the origin of several enzymes found in the mitochondria-derived organelles of anaerobic eukaryotes such as Trichomonas and Entamoeba. These enzymes are thought to derive from bacterial lineages other than α proteobacteria, e.g., Clostridium - an obligate anaerobe. [FeFe]-hydrogenase constitues the characteristic enzyme of this anaerobic metabolism and is present in different types also in Entamoeba and other anaerobic eukaryotes. Here we show that α proteobacteria derived from metagenomic studies possess both the cytosolic and organellar type of [FeFe]-hydrogenase, as well as all the proteins required for hydrogenase maturation. These organisms are related to cultivated members of the Rhodospirillales order previously suggested to be close relatives of mitochondrial ancestors. For the first time, our evidence supports an α proteobacterial ancestry for both the anaerobic and the aerobic metabolism of eukaryotes.REVIEWERS: This article was reviewed by William Martin and Nick Lane, both suggested by the Authors.

AB - UNLABELLED: Eukaryogenesis, a major transition in evolution of life, originated from the symbiogenic fusion of an archaea with a metabolically versatile bacterium. By general consensus, the latter organism belonged to α proteobacteria, subsequently evolving into the mitochondrial organelle of our cells. The consensus is based upon genetic and metabolic similarities between mitochondria and aerobic α proteobacteria but fails to explain the origin of several enzymes found in the mitochondria-derived organelles of anaerobic eukaryotes such as Trichomonas and Entamoeba. These enzymes are thought to derive from bacterial lineages other than α proteobacteria, e.g., Clostridium - an obligate anaerobe. [FeFe]-hydrogenase constitues the characteristic enzyme of this anaerobic metabolism and is present in different types also in Entamoeba and other anaerobic eukaryotes. Here we show that α proteobacteria derived from metagenomic studies possess both the cytosolic and organellar type of [FeFe]-hydrogenase, as well as all the proteins required for hydrogenase maturation. These organisms are related to cultivated members of the Rhodospirillales order previously suggested to be close relatives of mitochondrial ancestors. For the first time, our evidence supports an α proteobacterial ancestry for both the anaerobic and the aerobic metabolism of eukaryotes.REVIEWERS: This article was reviewed by William Martin and Nick Lane, both suggested by the Authors.

KW - Alphaproteobacteria/genetics

KW - Amino Acid Sequence

KW - Bacterial Proteins/genetics

KW - Evolution, Molecular

KW - Gastrointestinal Microbiome/genetics

KW - Humans

KW - Hydrogenase/genetics

KW - Phylogeny

KW - Rhodospirillaceae/genetics

U2 - 10.1186/s13062-016-0136-3

DO - 10.1186/s13062-016-0136-3

M3 - Journal article

C2 - 27473689

VL - 11

SP - 34

JO - Biology Direct

JF - Biology Direct

SN - 1745-6150

ER -