The archaeal-bacterial lipid divide, could a distinct lateral proton route hold the answer?

Mencı́a, Mario

doi:10.1186/s13062-020-00262-7

Cited by 12 publications

(5 citation statements)

References 58 publications

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“…Notably, these two modules correspond to the pathways in which A501 and 3DAC should be distinct. The module from DHAP to G13P2 is the link to the biosynthesis of lipids, representing the major difference between archaea and bacteria 50 , 51 . The other is in the biosynthesis of NAD(P) + from the precursor nicotinate.…”

Section: Resultsmentioning

confidence: 99%

Proteome-wide 3D structure prediction provides insights into the ancestral metabolism of ancient archaea and bacteria

et al. 2022

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Ancestral metabolism has remained controversial due to a lack of evidence beyond sequence-based reconstructions. Although prebiotic chemists have provided hints that metabolism might originate from non-enzymatic protometabolic pathways, gaps between ancestral reconstruction and prebiotic processes mean there is much that is still unknown. Here, we apply proteome-wide 3D structure predictions and comparisons to investigate ancestorial metabolism of ancient bacteria and archaea, to provide information beyond sequence as a bridge to the prebiotic processes. We compare representative bacterial and archaeal strains, which reveal surprisingly similar physiological and metabolic characteristics via microbiological and biophysical experiments. Pairwise comparison of protein structures identify the conserved metabolic modules in bacteria and archaea, despite interference from overly variable sequences. The conserved modules (for example, middle of glycolysis, partial TCA, proton/sulfur respiration, building block biosynthesis) constitute the basic functions that possibly existed in the archaeal-bacterial common ancestor, which are remarkably consistent with the experimentally confirmed protometabolic pathways. These structure-based findings provide a new perspective to reconstructing the ancestral metabolism and understanding its origin, which suggests high-throughput protein 3D structure prediction is a promising approach, deserving broader application in future ancestral exploration.

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Section: Resultsmentioning

confidence: 99%

Proteome-wide 3D structure prediction provides insights into the ancestral metabolism of ancient archaea and bacteria

et al. 2022

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“…For the bacterial premitochondrion, the loss of protons would not have been critical, (i) because bacteria have mechanisms to compensate pH shifts in any of the two directions in the environment, [ 74 ] (ii) the energetic loss involved would be compensated by the more efficient digestion, and (iii) a published hypothesis points to a special, more protected, proton route within the bacterial membrane. [ 75 ] In this scenario, acidification of the phagocytic microenvironment could potentially be more intense as it is driven by oxidative respiration.…”

Section: Resultsmentioning

confidence: 99%

Acid digestion and symbiont: Proton sharing at the origin of mitochondriogenesis?

Mencı́a

2022

BioEssays

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The initial relationships between organisms leading to endosymbiosis and the first eukaryote are currently a topic of hot debate. Here, I present a theory that offers a gradual scenario in which the origins of phagocytosis and mitochondria are intertwined in such a way that the evolution of one would not be possible without the other. In this scenario, the premitochondrial bacterial symbiont became initially associated with a protophagocytic host on the basis of cooperation to kill prey with symbiont‐produced toxins and reactive oxygen species (ROS). Subsequently, the cooperation was focused on the digestion stage, through the acidification of the protophagocytic cavities via exportation of protons produced by the aerobic respiration of the symbiont. The host gained an improved phagocytic capacity and the symbiont received organic compounds from prey. As the host gradually lost its membrane energetics to develop lysosomal digestion, respiration was centralized in the premitochondrial symbiont for energy production for the consortium.

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“…The cristae formation is functional to better functioning of membrane H + capacitor for better functionality of ATP synthase [ 29 ]. The H + handling was also analysed and it was found that bacterial phospholipid esters enable better H + lateral currents when in a monolayer over water than the isoprenoid phospholipid ethers of archaea [ 30 ]. This is confirmatory of H + currents on the membrane for energy transfer.…”

Section: A Novel Perspective On Mitochondria Evolutionmentioning

confidence: 99%

“…Along this vision, theoretically, any membrane can be considered as a ‘proton-sponge’ on the basis of the available pH-buffers in the form of phospholipids, which with their phosphate residue can store and dispose of protons at the membrane–cytosol interface [ 43 , 44 ]. The crucial role of the bacterial phospholipid ester to allow the H + current which entails interesting evolutionary considerations was recently highlighted [ 30 ]. On the other hand, the existence of H + conductors [ 45 – 47 ] and of H + microcircuits in membranes has been highlighted [ 48 ].…”

Section: Proton Movements In the Respiring Membranementioning

confidence: 99%

The aerobic mitochondrial ATP synthesis from a comprehensive point of view

2020

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Most of the ATP to satisfy the energetic demands of the cell is produced by the F 1 F o -ATP synthase (ATP synthase) which can also function outside the mitochondria. Active oxidative phosphorylation (OxPhos) was shown to operate in the photoreceptor outer segment, myelin sheath, exosomes, microvesicles, cell plasma membranes and platelets. The mitochondria would possess the exclusive ability to assemble the OxPhos molecular machinery so to share it with the endoplasmic reticulum (ER) and eventually export the ability to aerobically synthesize ATP in true extra-mitochondrial districts. The ER lipid rafts expressing OxPhos components is indicative of the close contact of the two organelles, bearing different evolutionary origins, to maximize the OxPhos efficiency, exiting in molecular transfer from the mitochondria to the ER. This implies that its malfunctioning could trigger a generalized oxidative stress. This is consistent with the most recent interpretations of the evolutionary symbiotic process whose necessary prerequisite appears to be the presence of the internal membrane system inside the eukaryote precursor, of probable archaeal origin allowing the engulfing of the α-proteobacterial precursor of mitochondria. The process of OxPhos in myelin is here studied in depth. A model is provided contemplating the biface arrangement of the nanomotor ATP synthase in the myelin sheath.

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The archaeal-bacterial lipid divide, could a distinct lateral proton route hold the answer?

Cited by 12 publications

References 58 publications

Proteome-wide 3D structure prediction provides insights into the ancestral metabolism of ancient archaea and bacteria

Proteome-wide 3D structure prediction provides insights into the ancestral metabolism of ancient archaea and bacteria

Acid digestion and symbiont: Proton sharing at the origin of mitochondriogenesis?

The aerobic mitochondrial ATP synthesis from a comprehensive point of view

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