Histones predate the split between bacteria and archaea

2018 ◽  
Vol 35 (14) ◽  
pp. 2349-2353 ◽  
Author(s):  
Vikram Alva ◽  
Andrei N Lupas
Keyword(s):  
Genomic Dna ◽  
Common Ancestor ◽  
Supplementary Information ◽  
Common Ancestry ◽  
Single Chain ◽  
Last Universal Common Ancestor ◽  
Universal Common Ancestor ◽  
Sequence Patterns ◽  
Subsequent Identification

Abstract Motivation Histones form octameric complexes called nucleosomes, which organize the genomic DNA of eukaryotes into chromatin. Each nucleosome comprises two copies each of the histones H2A, H2B, H3 and H4, which share a common ancestry. Although histones were initially thought to be a eukaryotic innovation, the subsequent identification of archaeal homologs led to the notion that histones emerged before the divergence of archaea and eukaryotes. Results Here, we report the detection and classification of two new groups of histone homologs, which are present in both archaea and bacteria. Proteins in one group consist of two histone subunits welded into single-chain pseudodimers, whereas in the other they resemble eukaryotic core histone subunits and show sequence patterns characteristic of DNA binding. The sequences come from a broad spectrum of deeply-branching lineages, excluding their genesis by horizontal gene transfer. Our results extend the origin of histones to the last universal common ancestor. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Phenotypic reconstruction of the last universal common ancestor reveals a complex cell

2020 ◽  
Author(s):  
Fouad El Baidouri ◽  
Chris Venditti ◽  
Sei Suzuki ◽  
Andrew Meade ◽  
Stuart Humphries
Keyword(s):  
Phylogenetic Trees ◽  
Common Ancestor ◽  
Evolutionary Model ◽  
Supplementary Information ◽  
Phenotypic Traits ◽  
Complex Cell ◽  
Last Universal Common Ancestor ◽  
Archaeal Species ◽  
Universal Common Ancestor ◽  
Living Organisms

AbstractA fundamental concept in evolutionary theory is the last universal common ancestor (LUCA) from which all living organisms. While some authors have suggested a relatively complex LUCA 1 it is still widely assumed that LUCA must have been a very simple cell and that life has subsequently increased in complexity through time 2,3. However, while current thought does tend towards a general increase in complexity through time in Eukaryotes 4,5, there is increasing evidence that bacteria and archaea have undergone considerable genome reduction during their evolution 6,7. This raises the surprising possibility that LUCA, as the ancestor of bacteria and archaea may have been a considerably complex cell. While hypotheses regarding the phenotype of LUCA do exist, all are founded on gene presence/absence 1–3. Yet, despite recent attempts to link genes and phenotypic traits in prokaryotes 8,9, it is still inherently difficult to predict phenotype based on the presence or absence of genes alone. In response to this, we used Bayesian phylogenetic comparative methods 10,11 to predict ancestral traits. Testing for robustness to horizontal gene transfer (HGT) we inferred the phenotypic traits of LUCA using two robust published phylogenetic trees 12,13 and a dataset of 3,128 bacterial and archaeal species (Supplementary Information). Our results depict LUCA as a far more complex cell than has previously been proposed, challenging the evolutionary model of increased complexity through time in prokaryotes. Given current estimates for the emergence of LUCA we suggest that early life very rapidly evolved considerable cellular complexity.

scholarly journals SepF is the FtsZ anchor in archaea, with features of an ancestral cell division system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nika Pende ◽  
Adrià Sogues ◽  
Daniela Megrian ◽  
Anna Sartori-Rupp ◽  
Patrick England ◽  
...  
Keyword(s):  
Cell Division ◽  
Common Ancestor ◽  
Phylogenetic Analyses ◽  
Super Resolution ◽  
Binding Mode ◽  
Last Universal Common Ancestor ◽  
Division Plane ◽  
Multiple Factors ◽  
Universal Common Ancestor ◽  
Super Resolution Microscopy

AbstractMost archaea divide by binary fission using an FtsZ-based system similar to that of bacteria, but they lack many of the divisome components described in model bacterial organisms. Notably, among the multiple factors that tether FtsZ to the membrane during bacterial cell constriction, archaea only possess SepF-like homologs. Here, we combine structural, cellular, and evolutionary analyses to demonstrate that SepF is the FtsZ anchor in the human-associated archaeon Methanobrevibacter smithii. 3D super-resolution microscopy and quantitative analysis of immunolabeled cells show that SepF transiently co-localizes with FtsZ at the septum and possibly primes the future division plane. M. smithii SepF binds to membranes and to FtsZ, inducing filament bundling. High-resolution crystal structures of archaeal SepF alone and in complex with the FtsZ C-terminal domain (FtsZCTD) reveal that SepF forms a dimer with a homodimerization interface driving a binding mode that is different from that previously reported in bacteria. Phylogenetic analyses of SepF and FtsZ from bacteria and archaea indicate that the two proteins may date back to the Last Universal Common Ancestor (LUCA), and we speculate that the archaeal mode of SepF/FtsZ interaction might reflect an ancestral feature. Our results provide insights into the mechanisms of archaeal cell division and pave the way for a better understanding of the processes underlying the divide between the two prokaryotic domains.

scholarly journals Origin of Life

2021 ◽  
Vol 83 (2) ◽  
pp. 76-79
Author(s):  
Cristina Sousa
Keyword(s):  
Origin Of Life ◽  
Common Ancestor ◽  
Scientific Evidence ◽  
Recent Common Ancestor ◽  
Last Universal Common Ancestor ◽  
Most Recent Common Ancestor ◽  
Universal Common Ancestor ◽  
The Origin Of Life

The origin of life is one of the most interesting and challenging questions in biology. This article discusses relevant contemporary theories and hypotheses about the origin of life, recent scientific evidence supporting them, and the main contributions of several scientists of different nationalities and specialties in different disciplines. Also discussed are several ideas about the characteristics of the most recent common ancestor, also called the “last universal common ancestor” (or LUCA), including cellular status (unicellular or community) and homogeneity level.

Evolution of biosynthetic diversity

2017 ◽  
Vol 474 (14) ◽  
pp. 2277-2299 ◽  
Author(s):  
Anthony J. Michael
Keyword(s):  
Common Ancestor ◽  
Polyamine Metabolism ◽  
Last Common Ancestor ◽  
Protein Fold ◽  
Last Universal Common Ancestor ◽  
Endosymbiotic Gene Transfer ◽  
Evolutionary Mechanisms ◽  
Universal Common Ancestor ◽  
Genes Encoding ◽  
Domains Of Life

Since the emergence of the last common ancestor from which all extant life evolved, the metabolite repertoire of cells has increased and diversified. Not only has the metabolite cosmos expanded, but the ways in which the same metabolites are made have diversified. Enzymes catalyzing the same reaction have evolved independently from different protein folds; the same protein fold can produce enzymes recognizing different substrates, and enzymes performing different chemistries. Genes encoding useful enzymes can be transferred between organisms and even between the major domains of life. Organisms that live in metabolite-rich environments sometimes lose the pathways that produce those same metabolites. Fusion of different protein domains results in enzymes with novel properties. This review will consider the major evolutionary mechanisms that generate biosynthetic diversity: gene duplication (and gene loss), horizontal and endosymbiotic gene transfer, and gene fusion. It will also discuss mechanisms that lead to convergence as well as divergence. To illustrate these mechanisms, one of the original metabolisms present in the last universal common ancestor will be employed: polyamine metabolism, which is essential for the growth and cell proliferation of archaea and eukaryotes, and many bacteria.

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