scholarly journals Thermotoga lettingae Can Salvage Cobinamide To Synthesize Vitamin B12

2013 ◽  
Vol 79 (22) ◽  
pp. 7006-7012 ◽  
Author(s):  
Nicholas C. Butzin ◽  
Michael A. Secinaro ◽  
Kristen S. Swithers ◽  
J. Peter Gogarten ◽  
Kenneth M. Noll
Keyword(s):  
Gene Cluster ◽  
Common Ancestor ◽  
De Novo ◽  
Recent Common Ancestor ◽  
Vitamin B ◽  
Ancestral State ◽  
Salvage Pathway ◽  
Content Type ◽  
Most Recent Common Ancestor

ABSTRACTWe recently reported that theThermotogalesacquired the ability to synthesize vitamin B12by acquisition of genes from two distantly related lineages,ArchaeaandFirmicutes(K. S. Swithers et al., Genome Biol. Evol. 4:730–739, 2012). Ancestral state reconstruction suggested that the cobinamide salvage gene cluster was present in theThermotogales' most recent common ancestor. We also predicted thatThermotoga lettingaecould not synthesize B12de novobut could use the cobinamide salvage pathway to synthesize B12. In this study, these hypotheses were tested, and we found thatTt. lettingaedid not synthesize B12de novobut salvaged cobinamide. The growth rate ofTt. lettingaeincreased with the addition of B12or cobinamide to its medium. It synthesized B12when the medium was supplemented with cobinamide, and no B12was detected in cells grown on cobinamide-deficient medium. Upstream of the cobinamide salvage genes is a putative B12riboswitch. In other organisms, B12riboswitches allow for higher transcriptional activity in the absence of B12. WhenTt. lettingaewas grown with no B12, the salvage genes were upregulated compared to cells grown with B12or cobinamide. Another gene cluster with a putative B12riboswitch upstream is thebtuFCDABC transporter, and it showed a transcription pattern similar to that of the cobinamide salvage genes. The BtuF proteins from species that can and cannot salvage cobinamides were shownin vitroto bind both B12and cobinamide. These results suggest thatThermotogalesspecies can use the BtuFCD transporter to import both B12and cobinamide, even if they cannot salvage cobinamide.

scholarly journals Impact of Vitamin B12on Formation of the Tetrachloroethene Reductive Dehalogenase in Desulfitobacterium hafniense Strain Y51

2012 ◽  
Vol 78 (22) ◽  
pp. 8025-8032 ◽  
Author(s):  
Anika Reinhold ◽  
Martin Westermann ◽  
Jana Seifert ◽  
Martin von Bergen ◽  
Torsten Schubert ◽  
...  
Keyword(s):  
Gene Cluster ◽  
De Novo ◽  
Anaerobic Bacteria ◽  
Vitamin B ◽  
Content Type ◽  
Reductive Dehalogenase ◽  
Gene Level ◽  
Desulfitobacterium Hafniense ◽  
Pce Dehalogenase ◽  
The Impact

ABSTRACTCorrinoids are essential cofactors of reductive dehalogenases in anaerobic bacteria. Microorganisms mediating reductive dechlorination as part of their energy metabolism are either capable ofde novocorrinoid biosynthesis (e.g.,Desulfitobacteriumspp.) or dependent on exogenous vitamin B12(e.g.,Dehalococcoidesspp.). In this study, the impact of exogenous vitamin B12(cyanocobalamin) and of tetrachloroethene (PCE) on the synthesis and the subcellular localization of the reductive PCE dehalogenase was investigated in the Gram-positiveDesulfitobacterium hafniensestrain Y51, a bacterium able to synthesize corrinoidsde novo. PCE-depleted cells grown for several subcultivation steps on fumarate as an alternative electron acceptor lost the tetrachloroethene-reductive dehalogenase (PceA) activity by the transposition of thepcegene cluster. In the absence of vitamin B12, a gradual decrease of the PceA activity and protein amount was observed; after 5 subcultivation steps with 10% inoculum, more than 90% of the enzyme activity and of the PceA protein was lost. In the presence of vitamin B12, a significant delay in the decrease of the PceA activity with an ∼90% loss after 20 subcultivation steps was observed. This corresponded to the decrease in thepceAgene level, indicating that exogenous vitamin B12hampered the transposition of thepcegene cluster. In the absence or presence of exogenous vitamin B12, the intracellular corrinoid level decreased in fumarate-grown cells and the PceA precursor formed catalytically inactive, corrinoid-free multiprotein aggregates. The data indicate that exogenous vitamin B12is not incorporated into the PceA precursor, even though it affects the transposition of thepcegene cluster.

scholarly journals Flexible Cobamide Metabolism in Clostridioides (Clostridium) difficile 630 Δerm

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Amanda N. Shelton ◽  
Xun Lyu ◽  
Michiko E. Taga
Keyword(s):  
De Novo ◽  
Aminolevulinic Acid ◽  
Genomic Analysis ◽  
Opportunistic Pathogen ◽  
Vitamin B ◽  
Uptake System ◽  
Human Gut ◽  
Content Type ◽  
Clostridioides Difficile

ABSTRACT Clostridioides (Clostridium) difficile is an opportunistic pathogen known for its ability to colonize the human gut under conditions of dysbiosis. Several aspects of its carbon and amino acid metabolism have been investigated, but its cobamide (vitamin B12 and related cofactors) metabolism remains largely unexplored. C. difficile has seven predicted cobamide-dependent pathways encoded in its genome in addition to a nearly complete cobamide biosynthesis pathway and a cobamide uptake system. To address the importance of cobamides to C. difficile, we studied C. difficile 630 Δerm and mutant derivatives under cobamide-dependent conditions in vitro. Our results show that C. difficile can use a surprisingly diverse array of cobamides for methionine and deoxyribonucleotide synthesis and can use alternative metabolites or enzymes, respectively, to bypass these cobamide-dependent processes. C. difficile 630 Δerm produces the cobamide pseudocobalamin when provided the early precursor 5-aminolevulinic acid or the late intermediate cobinamide (Cbi) and produces other cobamides if provided an alternative lower ligand. The ability of C. difficile 630 Δerm to take up cobamides and Cbi at micromolar or lower concentrations requires the transporter BtuFCD. Genomic analysis revealed genetic variations in the btuFCD loci of different C. difficile strains, which may result in differences in the ability to take up cobamides and Cbi. These results together demonstrate that, like other aspects of its physiology, cobamide metabolism in C. difficile is versatile. IMPORTANCE The ability of the opportunistic pathogen Clostridioides difficile to cause disease is closely linked to its propensity to adapt to conditions created by dysbiosis of the human gut microbiota. The cobamide (vitamin B12) metabolism of C. difficile has been underexplored, although it has seven metabolic pathways that are predicted to require cobamide-dependent enzymes. Here, we show that C. difficile cobamide metabolism is versatile, as it can use a surprisingly wide variety of cobamides and has alternative functions that can bypass some of its cobamide requirements. Furthermore, C. difficile does not synthesize cobamides de novo but produces them when given cobamide precursors. A better understanding of C. difficile cobamide metabolism may lead to new strategies to treat and prevent C. difficile-associated disease.

scholarly journals Draft Genome Sequence of a Potentially Novel Streptococcus Species Belonging to the Streptococcus mitis Group

2018 ◽  
Vol 6 (26) ◽  
Author(s):  
Ingerid Ø. Kirkeleite ◽  
Jon Bohlin ◽  
Lonneke Scheffer ◽  
Einar T. Weme ◽  
Didrik F. Vestrheim
Keyword(s):  
Species Identification ◽  
Genome Sequence ◽  
Common Ancestor ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Recent Common Ancestor ◽  
Streptococcus Mitis ◽  
Content Type ◽  
Streptococcus Species ◽  
Most Recent Common Ancestor

We report here the draft genome sequence of a Streptococcus species belonging to the S. mitis group. While a clear species identification cannot be made for the isolate, it appears that its most recent common ancestor is the species S. pseudopneumoniae.

scholarly journals Recombination and lineage-specific mutations led to the emergence of SARS-CoV-2

2020 ◽  
Author(s):  
Juan Ángel Patiño-Galindo ◽  
Ioan Filip ◽  
Mohammed AlQuraishi ◽  
Raul Rabadan
Keyword(s):  
Recombination Event ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Ancestral State ◽  
Genetic Characteristics ◽  
Spike Gene ◽  
Most Recent Common Ancestor ◽  
Zoonotic Viruses ◽  
Common Process ◽  
Recent Outbreak

AbstractThe recent outbreak of a new coronavirus (SARS-CoV-2) in Wuhan, China, underscores the need for understanding the evolutionary processes that drive the emergence and adaptation of zoonotic viruses in humans. Here, we show that recombination in betacoronaviruses, including human-infecting viruses like SARS-CoV and MERS-CoV, frequently encompasses the Receptor Binding Domain (RBD) in the Spike gene. We find that this common process likely led to a recombination event at least 11 years ago in an ancestor of the SARS-CoV-2 involving the RBD. As a result of this recombination event, SARS-CoV and SARS-CoV-2 share a similar genotype in RBD, including two insertions (positions 432-436 and 460-472), and alleles 427N and 436Y. Both 427N and 436Y belong to a helix that interacts with the human ACE2 receptor. Ancestral state analyses revealed that SARS-CoV-2 differentiated from its most recent common ancestor with RaTG13 by accumulating a significant number of amino acid changes in the RBD. In sum, we propose a two-hit scenario in the emergence of the SARS-CoV-2 virus whereby the SARS-CoV-2 ancestors in bats first acquired genetic characteristics of SARS-CoV by incorporation of a SARS-like RBD through recombination before 2009, and subsequently, the lineage that led to SARS-CoV-2 accumulated further, unique changes specifically in the RBD.

scholarly journals Treponema pallidum genome sequencing from six continents reveals variability in vaccine candidate genes and dominance of Nichols clade strains in Madagascar

2021 ◽  
Vol 15 (12) ◽  
pp. e0010063
Author(s):  
Nicole A. P. Lieberman ◽  
Michelle J. Lin ◽  
Hong Xie ◽  
Lasata Shrestha ◽  
Tien Nguyen ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum ◽  
Temporal Analysis ◽  
Recent Common Ancestor ◽  
Effective Vaccine ◽  
Most Recent Common Ancestor ◽  
Genes Encoding ◽  
Critical Resource

In spite of its immutable susceptibility to penicillin, Treponema pallidum (T. pallidum) subsp. pallidum continues to cause millions of cases of syphilis each year worldwide, resulting in significant morbidity and mortality and underscoring the urgency of developing an effective vaccine to curtail the spread of the infection. Several technical challenges, including absence of an in vitro culture system until very recently, have hampered efforts to catalog the diversity of strains collected worldwide. Here, we provide near-complete genomes from 196 T. pallidum strains–including 191 T. pallidum subsp. pallidum–sequenced directly from patient samples collected from 8 countries and 6 continents. Maximum likelihood phylogeny revealed that samples from most sites were predominantly SS14 clade. However, 99% (84/85) of the samples from Madagascar formed two of the five distinct Nichols subclades. Although recombination was uncommon in the evolution of modern circulating strains, we found multiple putative recombination events between T. pallidum subsp. pallidum and subsp. endemicum, shaping the genomes of several subclades. Temporal analysis dated the most recent common ancestor of Nichols and SS14 clades to 1717 (95% HPD: 1543–1869), in agreement with other recent studies. Rates of SNP accumulation varied significantly among subclades, particularly among different Nichols subclades, and was associated in the Nichols A subclade with a C394F substitution in TP0380, a ERCC3-like DNA repair helicase. Our data highlight the role played by variation in genes encoding putative surface-exposed outer membrane proteins in defining separate lineages, and provide a critical resource for the design of broadly protective syphilis vaccines targeting surface antigens.

scholarly journals Genome sequencing of 196 Treponema pallidum strains from six continents reveals additional variability in vaccine candidate genes and dominance of Nichols clade strains in Madagascar

2021 ◽  
Author(s):  
Nicole AP Lieberman ◽  
Michelle J Lin ◽  
Hong Xie ◽  
Lasata Shretha ◽  
Tien Nguyen ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum ◽  
Temporal Analysis ◽  
Recent Common Ancestor ◽  
Effective Vaccine ◽  
Most Recent Common Ancestor ◽  
Genes Encoding ◽  
Critical Resource

In spite of its immutable susceptibility to penicillin, Treponema pallidum (T. pallidum) subsp. pallidum continues to cause millions of cases of syphilis each year worldwide, resulting in significant morbidity and mortality and underscoring the urgency of developing an effective vaccine to curtail the spread of the infection. Several technical challenges, including absence of an in vitro culture system until very recently, have hampered efforts to catalog the diversity of strains collected worldwide. Here, we provide near-complete genomes from 196 T. pallidum strains, including 191 T. pallidum subsp. pallidum, sequenced directly from patient samples collected from 8 countries and 6 continents. Maximum likelihood phylogeny revealed that samples from most sites were predominantly SS14 clade. However, 99% (84/85) of the samples from Madagascar formed two of the five distinct Nichols subclades. Although recombination was uncommon in the evolution of modern circulating strains, we found multiple putative recombination events between T. pallidum subsp. pallidum and subsp. endemicum, shaping the genomes of several subclades. Temporal analysis dated the most recent common ancestor of Nichols and SS14 clades to 1717 (95% HPD: 1543-1869), in agreement with other recent studies. Rates of SNP accumulation varied significantly among subclades, particularly among different Nichols subclades, and was associated in the Nichols A subclade with a C394F substitution in TP0380, a ERCC3-like DNA repair helicase. Our data highlight the role played by variation in genes encoding putative surface-exposed outer membrane proteins in defining separate lineages, and provide a critical resource for the design of broadly protective syphilis vaccines targeting surface antigens.

scholarly journals On the Origin of Candida auris: Ancestor, Environmental Stresses, and Antiseptics

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. e02102-20
Author(s):  
Megha Sharma ◽  
Arunaloke Chakrabarti
Keyword(s):  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Future Research ◽  
Candida Auris ◽  
Content Type ◽  
Health Care Settings ◽  
Most Recent Common Ancestor ◽  
Scientific Facts ◽  
Geographical Locations ◽  
Opportunist Pathogen

ABSTRACTCandida auris has emerged as a serious threat to the health care settings. Advancements in molecular biology have provided several insights into the evolution of C. auris since it was first described in 2009. However, the simultaneous emergence of four different clades of the fungus at distinct geographical locations remains a mystery. The hypotheses already proposed by researchers fall short of explaining how and why C. auris emerged. In this article, we theorize that C. auris emerged from a common ancestor, subsequently migrated to specific geographical locations, and diversified genetically. This hypothesis is supported by genomic insights, historical events, and indirect scientific facts. C. auris adapted to humans at locations and times coinciding with the divergence from the most recent common ancestor, emerging almost simultaneously as an opportunist pathogen due to antiseptic practices. Future research will support or refute this hypothesis.

scholarly journals Allelic Genealogies in Sporophytic Self-Incompatibility Systems in Plants

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1187-1198 ◽  
Author(s):  
Mikkel H Schierup ◽  
Xavier Vekemans ◽  
Freddy B Christiansen
Keyword(s):  
Dominance Hierarchy ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Self Incompatibility ◽  
Most Recent Common Ancestor ◽  
Dominance Interactions ◽  
Turnover Process ◽  
Neutral Gene ◽  
Interspecific Comparisons ◽  
Coalescence Times

Abstract Expectations for the time scale and structure of allelic genealogies in finite populations are formed under three models of sporophytic self-incompatibility. The models differ in the dominance interactions among the alleles that determine the self-incompatibility phenotype: In the SSIcod model, alleles act codominantly in both pollen and style, in the SSIdom model, alleles form a dominance hierarchy, and in SSIdomcod, alleles are codominant in the style and show a dominance hierarchy in the pollen. Coalescence times of alleles rarely differ more than threefold from those under gametophytic self-incompatibility, and transspecific polymorphism is therefore expected to be equally common. The previously reported directional turnover process of alleles in the SSIdomcod model results in coalescence times lower and substitution rates higher than those in the other models. The SSIdom model assumes strong asymmetries in allelic action, and the most recessive extant allele is likely to be the most recent common ancestor. Despite these asymmetries, the expected shape of the allele genealogies does not deviate markedly from the shape of a neutral gene genealogy. The application of the results to sequence surveys of alleles, including interspecific comparisons, is discussed.

scholarly journals Molecular epidemiological characteristics of echovirus 6 in mainland China: extensive circulation of genotype F from 2007 to 2018

2021 ◽  
Author(s):  
Wenjun Cheng ◽  
Tianjiao Ji ◽  
Shuaifeng Zhou ◽  
Yong Shi ◽  
Lili Jiang ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Mainland China ◽  
Recent Common Ancestor ◽  
Genetic Characteristics ◽  
Most Recent Common Ancestor ◽  
Significant Difference ◽  
Echovirus 6 ◽  
Epidemiological Characteristics ◽  
Highest Posterior Density ◽  
Genotype F

AbstractEchovirus 6 (E6) is associated with various clinical diseases and is frequently detected in environmental sewage. Despite its high prevalence in humans and the environment, little is known about its molecular phylogeography in mainland China. In this study, 114 of 21,539 (0.53%) clinical specimens from hand, foot, and mouth disease (HFMD) cases collected between 2007 and 2018 were positive for E6. The complete VP1 sequences of 87 representative E6 strains, including 24 strains from this study, were used to investigate the evolutionary genetic characteristics and geographical spread of E6 strains. Phylogenetic analysis based on VP1 nucleotide sequence divergence showed that, globally, E6 strains can be grouped into six genotypes, designated A to F. Chinese E6 strains collected between 1988 and 2018 were found to belong to genotypes C, E, and F, with genotype F being predominant from 2007 to 2018. There was no significant difference in the geographical distribution of each genotype. The evolutionary rate of E6 was estimated to be 3.631 × 10-3 substitutions site-1 year-1 (95% highest posterior density [HPD]: 3.2406 × 10-3-4.031 × 10-3 substitutions site-1 year-1) by Bayesian MCMC analysis. The most recent common ancestor of the E6 genotypes was traced back to 1863, whereas their common ancestor in China was traced back to around 1962. A small genetic shift was detected in the Chinese E6 population size in 2009 according to Bayesian skyline analysis, which indicated that there might have been an epidemic around that year.

scholarly journals The Ancestry of a Sample of Sequences Subject to Recombination

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1217-1228 ◽  
Author(s):  
Carsten Wiuf ◽  
Jotun Hein
Keyword(s):  
Genetic Distance ◽  
Population Size ◽  
Upper Bound ◽  
Recombination Rate ◽  
Common Ancestor ◽  
Recent Common Ancestor ◽  
Sequence Length ◽  
Most Recent Common Ancestor ◽  
The Mean ◽  
Mean Time

Abstract In this article we discuss the ancestry of sequences sampled from the coalescent with recombination with constant population size 2N. We have studied a number of variables based on simulations of sample histories, and some analytical results are derived. Consider the leftmost nucleotide in the sequences. We show that the number of nucleotides sharing a most recent common ancestor (MRCA) with the leftmost nucleotide is ≈log(1 + 4N Lr)/4Nr when two sequences are compared, where L denotes sequence length in nucleotides, and r the recombination rate between any two neighboring nucleotides per generation. For larger samples, the number of nucleotides sharing MRCA with the leftmost nucleotide decreases and becomes almost independent of 4N Lr. Further, we show that a segment of the sequences sharing a MRCA consists in mean of 3/8Nr nucleotides, when two sequences are compared, and that this decreases toward 1/4Nr nucleotides when the whole population is sampled. A measure of the correlation between the genealogies of two nucleotides on two sequences is introduced. We show analytically that even when the nucleotides are separated by a large genetic distance, but share MRCA, the genealogies will show only little correlation. This is surprising, because the time until the two nucleotides shared MRCA is reciprocal to the genetic distance. Using simulations, the mean time until all positions in the sample have found a MRCA increases logarithmically with increasing sequence length and is considerably lower than a theoretically predicted upper bound. On the basis of simulations, it turns out that important properties of the coalescent with recombinations of the whole population are reflected in the properties of a sample of low size.

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