scholarly journals Evolutionary history of carbon monoxide dehydrogenase/acetyl-CoA synthase, one of the oldest enzymatic complexes

2018 ◽  
Vol 115 (6) ◽  
pp. E1166-E1173 ◽  
Author(s):  
Panagiotis S. Adam ◽  
Guillaume Borrel ◽  
Simonetta Gribaldo
Keyword(s):  
Carbon Monoxide ◽  
Evolutionary History ◽  
Carbon Fixation ◽  
Functional Characterization ◽  
Carbon Monoxide Dehydrogenase ◽  
Evolutionary Analysis ◽  
Acetyl Coa ◽  
Universal Common Ancestor ◽  
History Of

Carbon monoxide dehydrogenase/acetyl-CoA synthase (CODH/ACS) is a five-subunit enzyme complex responsible for the carbonyl branch of the Wood–Ljungdahl (WL) pathway, considered one of the most ancient metabolisms for anaerobic carbon fixation, but its origin and evolutionary history have been unclear. While traditionally associated with methanogens and acetogens, the presence of CODH/ACS homologs has been reported in a large number of uncultured anaerobic lineages. Here, we have carried out an exhaustive phylogenomic study of CODH/ACS in over 6,400 archaeal and bacterial genomes. The identification of complete and likely functional CODH/ACS complexes in these genomes significantly expands its distribution in microbial lineages. The CODH/ACS complex displays astounding conservation and vertical inheritance over geological times. Rare intradomain and interdomain transfer events might tie into important functional transitions, including the acquisition of CODH/ACS in some archaeal methanogens not known to fix carbon, the tinkering of the complex in a clade of model bacterial acetogens, or emergence of archaeal–bacterial hybrid complexes. Once these transfers were clearly identified, our results allowed us to infer the presence of a CODH/ACS complex with at least four subunits in the last universal common ancestor (LUCA). Different scenarios on the possible role of ancestral CODH/ACS are discussed. Despite common assumptions, all are equally compatible with an autotrophic, mixotrophic, or heterotrophic LUCA. Functional characterization of CODH/ACS from a larger spectrum of bacterial and archaeal lineages and detailed evolutionary analysis of the WL methyl branch will help resolve this issue.

scholarly journals Insights into CO2Fixation Pathway ofClostridium autoethanogenumby Targeted Mutagenesis

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Fungmin Liew ◽  
Anne M. Henstra ◽  
Klaus Winzer ◽  
Michael Köpke ◽  
Sean D. Simpson ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Carbon Fixation ◽  
Carbon Monoxide Dehydrogenase ◽  
Targeted Mutagenesis ◽  
Heterotrophic Growth ◽  
Acetate Production ◽  
Acetyl Coa ◽  
Gas Fermentation ◽  
Acetogenic Bacteria ◽  
Clostridium Autoethanogenum

ABSTRACTThe future sustainable production of chemicals and fuels from nonpetrochemical resources and reduction of greenhouse gas emissions are two of the greatest societal challenges. Gas fermentation, which utilizes the ability of acetogenic bacteria such asClostridium autoethanogenumto grow and convert CO2and CO into low-carbon fuels and chemicals, could potentially provide solutions to both. Acetogens fix these single-carbon gases via the Wood-Ljungdahl pathway. Two enzyme activities are predicted to be essential to the pathway: carbon monoxide dehydrogenase (CODH), which catalyzes the reversible oxidation of CO to CO2, and acetyl coenzyme A (acetyl-CoA) synthase (ACS), which combines with CODH to form a CODH/ACS complex for acetyl-CoA fixation. Despite their pivotal role in carbon fixation, their functions have not been confirmedin vivo. By genetically manipulating all three CODH isogenes (acsA,cooS1, andcooS2) ofC. autoethanogenum, we highlighted the functional redundancies of CODH by demonstrating thatcooS1andcooS2are dispensable for autotrophy. Unexpectedly, thecooS1inactivation strain showed a significantly reduced lag phase and a higher growth rate than the wild type on H2and CO2. During heterotrophic growth on fructose, theacsAinactivation strain exhibited 61% reduced biomass and the abolishment of acetate production (a hallmark of acetogens), in favor of ethanol, lactate, and 2,3-butanediol production. A translational readthrough event was discovered in the uniquely truncated (compared to those of other acetogens)C. autoethanogenum acsAgene. Insights gained from studying the function of CODH enhance the overall understanding of autotrophy and can be used for optimization of biotechnological production of ethanol and other commodities via gas fermentation.IMPORTANCEGas fermentation is an emerging technology that converts the greenhouse gases CO2and CO in industrial waste gases and gasified biomass into fuels and chemical commodities. Acetogenic bacteria such asClostridium autoethanogenumare central to this bioprocess, but the molecular and genetic characterization of this microorganism is currently lacking. By targeting all three of the isogenes encoding carbon monoxide dehydrogenase (CODH) inC. autoethanogenum, we identified the most important CODH isogene for carbon fixation and demonstrated that genetic inactivation of CODH could improve autotrophic growth. This study shows that disabling of the Wood-Ljungdahl pathway via the inactivation ofacsA(encodes CODH) significantly impairs heterotrophic growth and alters the product profile by abolishing acetate production. Moreover, we discovered a previously undescribed mechanism for controlling the production of this enzyme. This study provides valuable insights into the acetogenic pathway and can be used for the development of more efficient and productive strains for gas fermentation.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

scholarly journals Molecular evolutionary analysis of human primary microcephaly genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nashaiman Pervaiz ◽  
Hongen Kang ◽  
Yiming Bao ◽  
Amir Ali Abbasi
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Brain Size ◽  
Primate Species ◽  
Evolutionary Analysis ◽  
Australopithecus Afarensis ◽  
Primary Microcephaly ◽  
Modern Humans ◽  
History Of ◽  
The Brain

Abstract Background There has been a rapid increase in the brain size relative to body size during mammalian evolutionary history. In particular, the enlarged and globular brain is the most distinctive anatomical feature of modern humans that set us apart from other extinct and extant primate species. Genetic basis of large brain size in modern humans has largely remained enigmatic. Genes associated with the pathological reduction of brain size (primary microcephaly-MCPH) have the characteristics and functions to be considered ideal candidates to unravel the genetic basis of evolutionary enlargement of human brain size. For instance, the brain size of microcephaly patients is similar to the brain size of Pan troglodyte and the very early hominids like the Sahelanthropus tchadensis and Australopithecus afarensis. Results The present study investigates the molecular evolutionary history of subset of autosomal recessive primary microcephaly (MCPH) genes; CEP135, ZNF335, PHC1, SASS6, CDK6, MFSD2A, CIT, and KIF14 across 48 mammalian species. Codon based substitutions site analysis indicated that ZNF335, SASS6, CIT, and KIF14 have experienced positive selection in eutherian evolutionary history. Estimation of divergent selection pressure revealed that almost all of the MCPH genes analyzed in the present study have maintained their functions throughout the history of placental mammals. Contrary to our expectations, human-specific adoptive evolution was not detected for any of the MCPH genes analyzed in the present study. Conclusion Based on these data it can be inferred that protein-coding sequence of MCPH genes might not be the sole determinant of increase in relative brain size during primate evolutionary history.

scholarly journals Gut bacteria are essential for normal cuticle development in herbivorous turtle ants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christophe Duplais ◽  
Vincent Sarou-Kanian ◽  
Dominique Massiot ◽  
Alia Hassan ◽  
Barbara Perrone ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Nitrogen Assimilation ◽  
Isotope Ratio Mass Spectrometry ◽  
Gut Bacteria ◽  
Resonance Spectroscopy ◽  
Nitrogen Flow ◽  
Isotopic Enrichment ◽  
History Of ◽  
Cuticle Development

AbstractAcross the evolutionary history of insects, the shift from nitrogen-rich carnivore/omnivore diets to nitrogen-poor herbivorous diets was made possible through symbiosis with microbes. The herbivorous turtle ants Cephalotes possess a conserved gut microbiome which enriches the nutrient composition by recycling nitrogen-rich metabolic waste to increase the production of amino acids. This enrichment is assumed to benefit the host, but we do not know to what extent. To gain insights into nitrogen assimilation in the ant cuticle we use gut bacterial manipulation, 15N isotopic enrichment, isotope-ratio mass spectrometry, and 15N nuclear magnetic resonance spectroscopy to demonstrate that gut bacteria contribute to the formation of proteins, catecholamine cross-linkers, and chitin in the cuticle. This study identifies the cuticular components which are nitrogen-enriched by gut bacteria, highlighting the role of symbionts in insect evolution, and provides a framework for understanding the nitrogen flow from nutrients through bacteria into the insect cuticle.

Early origin of sweet perception in the songbird radiation

Science ◽  
2021 ◽  
Vol 373 (6551) ◽  
pp. 226-231 ◽  
Author(s):  
Yasuka Toda ◽  
Meng-Ching Ko ◽  
Qiaoyi Liang ◽  
Eliot T. Miller ◽  
Alejandro Rico-Guevara ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Sensory Biology ◽  
Avian Evolution ◽  
Nectar Feeding ◽  
Evolutionary Radiation ◽  
History Of ◽  
Sensory Convergence ◽  
Early Origin

Early events in the evolutionary history of a clade can shape the sensory systems of descendant lineages. Although the avian ancestor may not have had a sweet receptor, the widespread incidence of nectar-feeding birds suggests multiple acquisitions of sugar detection. In this study, we identify a single early sensory shift of the umami receptor (the T1R1-T1R3 heterodimer) that conferred sweet-sensing abilities in songbirds, a large evolutionary radiation containing nearly half of all living birds. We demonstrate sugar responses across species with diverse diets, uncover critical sites underlying carbohydrate detection, and identify the molecular basis of sensory convergence between songbirds and nectar-specialist hummingbirds. This early shift shaped the sensory biology of an entire radiation, emphasizing the role of contingency and providing an example of the genetic basis of convergence in avian evolution.

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