scholarly journals Delineation of the Crucial Evolutionary Amino Acid Sites in Trehalose-6-Phosphate Synthase From Higher Plants

2020 ◽  
Vol 16 ◽  
pp. 117693432091014
Author(s):  
Rong Wang ◽  
Congfen He ◽  
Kun Dong ◽  
Xin Zhao ◽  
Yaxuan Li ◽  
...  

Trehalose-6-phosphate synthase (TPS) is a key enzyme in the biosynthesis of trehalose, with its direct product, trehalose-6-phosphate, playing important roles in regulating whole-plant carbohydrate allocation and utilization. Genes encoding TPS constitute a multigene family in which functional divergence appears to have occurred repeatedly. To identify the crucial evolutionary amino acid sites of TPS in higher plants, a series of bioinformatics tools were applied to investigate the phylogenetic relationships, functional divergence, positive selection, and co-evolution of TPS proteins. First, we identified 150 TPS genes from 13 higher plant species. Phylogenetic analysis placed these TPS proteins into 2 clades: clades A and B, of which clade B could be further divided into 4 subclades (B1-B4). This classification was supported by the intron-exon structures, with more introns present in clade A. Next, detection of the critical functionally divergent amino acid sites resulted in the isolation of a total of 286 sites reflecting nonredundant radical shifts in amino acid properties with a high posterior probability cutoff among subclades. In addition, positively selected sites were identified using a codon substitution model, from which 46 amino acid sites were isolated as exhibiting positive selection at a significant level. Moreover, 18 amino acid sites were highlighted both for functional divergence and positive selection; these may thus potentially represent crucial evolutionary sites in the TPS family. Further co-evolutionary analysis revealed 3 pairs of sites: 11S and 12H, 33S and 34N, and 109G and 110E as demonstrating co-evolution. Finally, the 18 crucial evolutionary amino acid sites were mapped in the 3-dimensional structure. A total of 77 sites harboring functionally and structurally important residues of TPS proteins were found by using the CLIPS-4D online tool; notably, no overlap was observed with the identified crucial evolutionary sites, providing positive evidence supporting their designation. A total of 18 sites were isolated as key amino acids by using multiple bioinformatics tools based on their concomitant functional divergence and positive selection. Almost all these key sites are located in 2 domains of this protein family where they exhibit no overlap with the structurally and functionally conserved sites. These results will provide an improved understanding of the complexity of the TPS gene family and of its function and evolution in higher plants. Moreover, this knowledge may facilitate the exploitation of these sites for protein engineering applications.

Genetics ◽  
2000 ◽  
Vol 155 (1) ◽  
pp. 431-449 ◽  
Author(s):  
Ziheng Yang ◽  
Rasmus Nielsen ◽  
Nick Goldman ◽  
Anne-Mette Krabbe Pedersen

AbstractComparison of relative fixation rates of synonymous (silent) and nonsynonymous (amino acid-altering) mutations provides a means for understanding the mechanisms of molecular sequence evolution. The nonsynonymous/synonymous rate ratio (ω = dN/dS) is an important indicator of selective pressure at the protein level, with ω = 1 meaning neutral mutations, ω < 1 purifying selection, and ω > 1 diversifying positive selection. Amino acid sites in a protein are expected to be under different selective pressures and have different underlying ω ratios. We develop models that account for heterogeneous ω ratios among amino acid sites and apply them to phylogenetic analyses of protein-coding DNA sequences. These models are useful for testing for adaptive molecular evolution and identifying amino acid sites under diversifying selection. Ten data sets of genes from nuclear, mitochondrial, and viral genomes are analyzed to estimate the distributions of ω among sites. In all data sets analyzed, the selective pressure indicated by the ω ratio is found to be highly heterogeneous among sites. Previously unsuspected Darwinian selection is detected in several genes in which the average ω ratio across sites is <1, but in which some sites are clearly under diversifying selection with ω > 1. Genes undergoing positive selection include the β-globin gene from vertebrates, mitochondrial protein-coding genes from hominoids, the hemagglutinin (HA) gene from human influenza virus A, and HIV-1 env, vif, and pol genes. Tests for the presence of positively selected sites and their subsequent identification appear quite robust to the specific distributional form assumed for ω and can be achieved using any of several models we implement. However, we encountered difficulties in estimating the precise distribution of ω among sites from real data sets.


PLoS ONE ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. e8885 ◽  
Author(s):  
Aristeidis Parmakelis ◽  
Marina Moustaka ◽  
Nikolaos Poulakakis ◽  
Christos Louis ◽  
Michel A. Slotman ◽  
...  

2012 ◽  
Vol 9 (3) ◽  
pp. 18-32 ◽  
Author(s):  
David Reboiro-Jato ◽  
Miguel Reboiro-Jato ◽  
Florentino Fdez-Riverola ◽  
Cristina P. Vieira ◽  
Nuno A. Fonseca ◽  
...  

Summary Maximum-likelihood methods based on models of codon substitution have been widely used to infer positively selected amino acid sites that are responsible for adaptive changes. Nevertheless, in order to use such an approach, software applications are required to align protein and DNA sequences, infer a phylogenetic tree and run the maximum-likelihood models. Therefore, a significant effort is made in order to prepare input files for the different software applications and in the analysis of the output of every analysis. In this paper we present the ADOPS (Automatic Detection Of Positively Selected Sites) software. It was developed with the goal of providing an automatic and flexible tool for detecting positively selected sites given a set of unaligned nucleotide sequence data. An example of the usefulness of such a pipeline is given by showing, under different conditions, positively selected amino acid sites in a set of 54 Coffea putative S-RNase sequences. ADOPS software is freely available and can be downloaded from http://sing.ei.uvigo.es/ADOPS.


2002 ◽  
Vol 19 (6) ◽  
pp. 950-958 ◽  
Author(s):  
Maria Anisimova ◽  
Joseph P. Bielawski ◽  
Ziheng Yang

2020 ◽  
Author(s):  
Yue Liu ◽  
Nannan Liu ◽  
Xiong Deng ◽  
Dongmiao Liu ◽  
Mengfei Li ◽  
...  

Abstract Background: DNA binding with one finger (Dof) transcription factors play important roles in plant growth and abiotic stress responses. Although genome-wide identification and analysis of the DOF transcription factor family has been reported in other species, no relevant studies have emerged in wheat. The aim of this study was to investigate the evolutionary and functional characteristics associated with plant growth and abiotic stress responses by genome-wide analysis of the wheat Dof transcription factor gene family. Results: Using the recently released wheat genome database (IWGSC RefSeq v1.1), we identified 96 wheat Dof gene family members, which were phylogenetically clustered into five distinct subfamilies. Gene duplication analysis revealed a broad and heterogeneous distribution of TaDofs on the chromosome groups 1 to 7, and obvious tandem duplication genes were present on chromosomes 2 and 3.Members of the same gene subfamily had similar exon-intron structures, while members of different subfamilies had obvious differences. Functional divergence analysis indicated that type-II functional divergence played a major role in the differentiation of the TaDof gene family. Positive selection analysis revealed that the Dof gene family experienced different degrees of positive selection pressure during the process of evolution, and five significant positive selection sites (30A, 31T, 33A, 102G and 104S) were identified. Additionally, nine groups of coevolving amino acid sites, which may play a key role in maintaining the structural and functional stability of Dof proteins, were identified. The results from the RNA-seq data and qRT-PCR analysis revealed that TaDof genes exhibited obvious expression preference or specificity in different organs and developmental stages, as well as in diverse abiotic stress responses. Most TaDof genes were significantly upregulated by heat, PEG and heavy metal stresses. Conclusions: The genome-wide analysis and identification of wheat DOF transcription factor family and the discovery of important amino acid sites are expected to provide new insights into the structure, evolution and function of the plant Dof gene family.


2020 ◽  
Vol 15 (1) ◽  
pp. 346-363
Author(s):  
Lingyan Meng ◽  
Xiaomei Liu ◽  
Congfen He ◽  
Biyao Xu ◽  
Yaxuan Li ◽  
...  

AbstractKNOTTED-like homeodomain (KNOX) genes are transcriptional regulators that play an important role in morphogenesis. In the present study, a comparative analysis was performed to investigate the molecular evolution of the characteristics of the KNOX gene family in 10 different plant species. We identified 129 KNOX gene family members, which were categorized into two subfamilies based on multiple sequence alignment and phylogenetic tree reconstruction. Several segmental duplication pairs were found, indicating that different species share a common expansion model. Functional divergence analysis identified the 15 and 52 amino acid sites with significant changes in evolutionary rates and amino acid physicochemical properties as functional divergence sites. Additional selection analysis showed that 14 amino acid sites underwent positive selection during evolution, and two groups of co-evolutionary amino acid sites were identified by Coevolution Analysis using Protein Sequences software. These sites could play critical roles in the molecular evolution of the KNOX gene family in these species. In addition, the expression profiles of KNOX duplicated genes demonstrated functional divergence. Taken together, these results provide novel insights into the structural and functional evolution of the KNOX gene family.


2018 ◽  
Author(s):  
Claudia C. Weber ◽  
Simon Whelan

AbstractSubstitutions between chemically distant amino acids are known to occur less frequently than those between more similar amino acids. This knowledge, however, is not reflected in most codon substitution models, which treat all non-synonymous changes as if they were equivalent in terms of impact on the protein. A variety of methods for integrating chemical distances into models have been proposed, with a common approach being to divide substitutions into radical or conservative categories. Nevertheless, it remains unclear whether the resulting models describe sequence evolution better than their simpler counterparts.We propose a parametric codon model that distinguishes between radical and conservative substitutions, allowing us to assess if radical substitutions are preferentially removed by selection. Applying our new model to a range of phylogenomic data, we find differentiating between radical and conservative substitutions provides significantly better fit for large populations, but see no equivalent improvement for smaller populations. Comparing codon- and amino acid models using these same data shows that alignments from large populations tend to select phylogenetic models containing information about amino acid exchangeabilities, whereas the structure of the genetic code is more important for smaller populations.Our results suggest selection against radical substitutions is, on average, more pronounced in large populations than smaller ones. The reduced observable effect of selection in smaller populations may be due to stronger genetic drift making it more challenging to detect preferences. Our results imply an important connection between the life history of a phylogenetic group and the model that best describes its evolution.


2018 ◽  
Vol 92 (12) ◽  
Author(s):  
Anna A. Schönherz ◽  
Roald Forsberg ◽  
Bernt Guldbrandtsen ◽  
Albert J. Buitenhuis ◽  
Katja Einer-Jensen

ABSTRACTViral hemorrhagic septicemia virus(VHSV), a rhabdovirus infecting teleost fish, has repeatedly crossed the boundary from marine fish species to freshwater cultured rainbow trout. These naturally replicated cross-species transmission events permit the study of general and repeatable evolutionary events occurring in connection with viral emergence in a novel host species. The purpose of the present study was to investigate the adaptive molecular evolution of the VHSV glycoprotein, one of the key virus proteins involved in viral emergence, following emergence from marine species into freshwater cultured rainbow trout. A comprehensive phylogenetic reconstruction of the complete coding region of the VHSV glycoprotein was conducted, and adaptive molecular evolution was investigated using a maximum likelihood approach to compare different codon substitution models allowing for heterogeneous substitution rate ratios among amino acid sites. Evidence of positive selection was detected at six amino acid sites of the VHSV glycoprotein, within the signal peptide, the confirmation-dependent major neutralizing epitope, and the intracellular tail. Evidence of positive selection was found exclusively in rainbow trout-adapted virus isolates, and amino acid combinations found at the six sites under positive selection pressure differentiated rainbow trout- from non-rainbow trout-adapted isolates. Furthermore, four adaptive sites revealed signs of recurring identical changes across phylogenetic groups of rainbow trout-adapted isolates, suggesting that repeated VHSV emergence in freshwater cultured rainbow trout was established through convergent routes of evolution that are associated with immune escape.IMPORTANCEThis study is the first to demonstrate that VHSV emergence from marine species into freshwater cultured rainbow trout has been accompanied by bursts of adaptive evolution in the VHSV glycoprotein. Furthermore, repeated detection of the same adaptive amino acid sites across phylogenetic groups of rainbow trout-adapted isolates indicates that adaptation to rainbow trout was established through parallel evolution. In addition, signals of convergent evolution toward the maintenance of genetic variation were detected in the conformation-dependent neutralizing epitope or in close proximity to disulfide bonds involved in the structural conformation of the neutralizing epitope, indicating adaptation to immune response-related genetic variation across freshwater cultured rainbow trout.


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