scholarly journals Identification of distinct characteristics of antibiofilm peptides and prospection of diverse sources for efficacious sequences

2021 ◽  
Author(s):  
Bipasa Bose ◽  
Taylor Downey ◽  
Anand K. Ramasubramanian ◽  
David C. Anastasiu
Keyword(s):  
Regression Model ◽  
Sequence Similarity ◽  
Drug Repurposing ◽  
Classification Model ◽  
Antibiofilm Activity ◽  
High Sequence Similarity ◽  
Small Molecule Drugs ◽  
Microbial Infections ◽  
Positive Dataset ◽  
Therapeutic Properties

A majority of microbial infections are associated with biofilms. Targeting biofilms is considered an effective strategy to limit microbial virulence while minimizing the development of antibiotic resistance. Towards this need, antibiofilm peptides are an attractive arsenal since they are bestowed with properties orthogonal to small molecule drugs. In this work, we developed machine learning models to identify the distinguishing characteristics of known antibiofilm peptides, and to mine peptide databases from diverse habitats to classify new peptides with potential antibiofilm activities. Additionally, we used the reported minimum inhibitory/eradication concentration (MBIC/MBEC) of the antibiofilm peptides to create a regression model on top of the classification model to predict the effectiveness of new antibiofilm peptides. We used a positive dataset containing 242 antibiofilm peptides, and a negative dataset which, unlike previous datasets, contains peptides that are likely to promote biofilm formation. Our model achieved a classification accuracy greater than 98% and harmonic mean of precision-recall (F1) and Matthews correlation coefficient (MCC) scores greater than 0.90; the regression model achieved an MCC score greater than 0.81. We utilized our classification-regression pipeline to evaluate 135,015 peptides from diverse sources and identified antibiofilm peptide candidates that are efficacious against preformed biofilms at micromolar concentrations. Structural analysis of the top 37 hits revealed a larger distribution of helices and coils than sheets. Sequence alignment of these hits with known antibiofilm peptides revealed that, while some of the hits showed relatively high sequence similarity with known peptides, some others did not indicate the presence of antibiofilm activity in novel sources or sequences. Further, some of the hits had previously recognized therapeutic properties or host defense traits suggestive of drug repurposing applications. Taken together, this work demonstrates a new in silicio approach to predicting antibiofilm efficacy, and identifies promising new candidates for biofilm eradication.

scholarly journals Efficient CRISPR/Cas9 mediated Pooled-sgRNAs assembly accelerates targeting multiple genes related to male sterility in cotton

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Mohamed Ramadan ◽  
Muna Alariqi ◽  
Yizan Ma ◽  
Yanlong Li ◽  
Zhenping Liu ◽  
...  
Keyword(s):  
Genetic Transformation ◽  
Sequence Similarity ◽  
High Specificity ◽  
Transformation Method ◽  
High Sequence Similarity ◽  
Single Experiment ◽  
Next Generation Sequencing Technology ◽  
Cotton Transformation ◽  
Assembly Method ◽  
Multiple Genes

Abstract Background Upland cotton (Gossypium hirsutum), harboring a complex allotetraploid genome, consists of A and D sub-genomes. Every gene has multiple copies with high sequence similarity that makes genetic, genomic and functional analyses extremely challenging. The recent accessibility of CRISPR/Cas9 tool provides the ability to modify targeted locus efficiently in various complicated plant genomes. However, current cotton transformation method targeting one gene requires a complicated, long and laborious regeneration process. Hence, optimizing strategy that targeting multiple genes is of great value in cotton functional genomics and genetic engineering. Results To target multiple genes in a single experiment, 112 plant development-related genes were knocked out via optimized CRISPR/Cas9 system. We optimized the key steps of pooled sgRNAs assembly method by which 116 sgRNAs pooled together into 4 groups (each group consisted of 29 sgRNAs). Each group of sgRNAs was compiled in one PCR reaction which subsequently went through one round of vector construction, transformation, sgRNAs identification and also one round of genetic transformation. Through the genetic transformation mediated Agrobacterium, we successfully generated more than 800 plants. For mutants identification, Next Generation Sequencing technology has been used and results showed that all generated plants were positive and all targeted genes were covered. Interestingly, among all the transgenic plants, 85% harbored a single sgRNA insertion, 9% two insertions, 3% three different sgRNAs insertions, 2.5% mutated sgRNAs. These plants with different targeted sgRNAs exhibited numerous combinations of phenotypes in plant flowering tissues. Conclusion All targeted genes were successfully edited with high specificity. Our pooled sgRNAs assembly offers a simple, fast and efficient method/strategy to target multiple genes in one time and surely accelerated the study of genes function in cotton.

scholarly journals Repurposing existing drugs for new uses: a cohort study of the frequency of FDA-granted new indication exclusivities since 1997

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Babak Sahragardjoonegani ◽  
Reed F. Beall ◽  
Aaron S. Kesselheim ◽  
Aidan Hollis
Keyword(s):  
Therapeutic Potential ◽  
Drug Repurposing ◽  
Status Quo ◽  
New Drugs ◽  
Generic Entry ◽  
Small Molecule Drugs ◽  
Clinical Investigations ◽  
Fda Approval ◽  
Limited Duration ◽  
Observation Period

Abstract Background Drug repurposing (i.e., finding novel uses for existing drugs) is essential for maximizing medicines’ therapeutic utility, but obtaining regulatory approval for new indications is costly. Policymakers have therefore created temporary indication-specific market exclusivities to incentivize drug innovators to run new clinical investigations. The effectiveness of these exclusivities is poorly understood. Objective To determine whether generic entry impacts the probability of new indication additions. Methods For a cohort of all new small-molecule drugs approved by the FDA between July 1997 and May 2020, we tracked new indications added for the subset of drugs that experienced generic entry during the observation period and then analyzed how the probability of a new indication changed with the number of years since/to generic entry. Results Of the 197 new drugs that subsequently experienced generic entry, only 64 (32%) had at least one new indication added. The probability of a new indication addition peaked above 4% between 7 and 8 years prior to generic entry and then to dropped to near zero 15 years after FDA approval. We show that the limited duration of exclusivity reduces the number of secondary indications significantly. Conclusion Status quo for most drug innovators is creating novel one-indication products. Despite indication-specific exclusivities, the imminence of generic entry still has a detectable impact on reducing the chances of new indication additions. There is much room for improvement when it comes to incentivizing clinical investigations for new uses and unlocking existing medicines’ full therapeutic potential.

scholarly journals Evolution of Chi motifs in Proteobacteria

2021 ◽  
Author(s):  
Angélique Buton ◽  
Louis-Marie Bobay
Keyword(s):  
Sequence Similarity ◽  
Bacterial Species ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Large Dataset ◽  
High Sequence Similarity ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Motif ◽  
And Staphylococcus Aureus

Abstract Homologous recombination is a key pathway found in nearly all bacterial taxa. The recombination complex allows bacteria to repair DNA double strand breaks but also promotes adaption through the exchange of DNA between cells. In Proteobacteria, this process is mediated by the RecBCD complex, which relies on the recognition of a DNA motif named Chi to initiate recombination. The Chi motif has been characterized in Escherichia coli and analogous sequences have been found in several other species from diverse families, suggesting that this mode of action is widespread across bacteria. However, the sequences of Chi-like motifs are known for only five bacterial species: E. coli, Haemophilus influenzae, Bacillus subtilis, Lactococcus lactis and Staphylococcus aureus. In this study we detected putative Chi motifs in a large dataset of Proteobacteria and we identified four additional motifs sharing high sequence similarity and similar properties to the Chi motif of E. coli in 85 species of Proteobacteria. Most Chi motifs were detected in Enterobacteriaceae and this motif appears well conserved in this family. However, we did not detect Chi motifs for the majority of Proteobacteria, suggesting that different motifs are used in these species. Altogether these results substantially expand our knowledge on the evolution of Chi motifs and on the recombination process in bacteria.

Meiotic Recombination Between Paralogous RBCSB Genes on Sister Chromatids of Arabidopsis thaliana

Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 947-957 ◽  
Author(s):  
John G Jelesko ◽  
Kristy Carter ◽  
Whitney Thompson ◽  
Yuki Kinoshita ◽  
Wilhelm Gruissem
Keyword(s):  
Gene Cluster ◽  
Dna Sequences ◽  
Meiotic Recombination ◽  
Sequence Similarity ◽  
Specific Gene ◽  
High Sequence Similarity ◽  
Paralogous Genes ◽  
Chimeric Genes ◽  
Unequal Recombination ◽  
Sister Chromatids

Abstract Paralogous genes organized as a gene cluster can rapidly evolve by recombination between misaligned paralogs during meiosis, leading to duplications, deletions, and novel chimeric genes. To model unequal recombination within a specific gene cluster, we utilized a synthetic RBCSB gene cluster to isolate recombinant chimeric genes resulting from meiotic recombination between paralogous genes on sister chromatids. Several F1 populations hemizygous for the synthRBCSB1 gene cluster gave rise to Luc+ F2 plants at frequencies ranging from 1 to 3 × 10-6. A nonuniform distribution of recombination resolution sites resulted in the biased formation of recombinant RBCS3B/1B::LUC genes with nonchimeric exons. The positioning of approximately half of the mapped resolution sites was effectively modeled by the fractional length of identical DNA sequences. In contrast, the other mapped resolution sites fit an alternative model in which recombination resolution was stimulated by an abrupt transition from a region of relatively high sequence similarity to a region of low sequence similarity. Thus, unequal recombination between paralogous RBCSB genes on sister chromatids created an allelic series of novel chimeric genes that effectively resulted in the diversification rather than the homogenization of the synthRBCSB1 gene cluster.

scholarly journals The Complete Chloroplast Genome of the Vulnerable Oreocharis esquirolii (Gesneriaceae): Structural Features, Comparative and Phylogenetic Analysis

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1692
Author(s):  
Li Gu ◽  
Ting Su ◽  
Ming-Tai An ◽  
Guo-Xiong Hu
Keyword(s):  
Phylogenetic Analysis ◽  
Sequence Similarity ◽  
Single Copy ◽  
Structural Features ◽  
Rrna Genes ◽  
Trna Genes ◽  
Sequencing Data ◽  
High Sequence Similarity ◽  
Plastid Genomes ◽  
Cp Genome

Oreocharis esquirolii, a member of Gesneriaceae, is known as Thamnocharis esquirolii, which has been regarded a synonym of the former. The species is endemic to Guizhou, southwestern China, and is evaluated as vulnerable (VU) under the International Union for Conservation of Nature (IUCN) criteria. Until now, the sequence and genome information of O. esquirolii remains unknown. In this study, we assembled and characterized the complete chloroplast (cp) genome of O. esquirolii using Illumina sequencing data for the first time. The total length of the cp genome was 154,069 bp with a typical quadripartite structure consisting of a pair of inverted repeats (IRs) of 25,392 bp separated by a large single copy region (LSC) of 85,156 bp and a small single copy region (SSC) of18,129 bp. The genome comprised 114 unique genes with 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. Thirty-one repeat sequences and 74 simple sequence repeats (SSRs) were identified. Genome alignment across five plastid genomes of Gesneriaceae indicated a high sequence similarity. Four highly variable sites (rps16-trnQ, trnS-trnG, ndhF-rpl32, and ycf 1) were identified. Phylogenetic analysis indicated that O. esquirolii grouped together with O. mileensis, supporting resurrection of the name Oreocharis esquirolii from Thamnocharisesquirolii. The complete cp genome sequence will contribute to further studies in molecular identification, genetic diversity, and phylogeny.

scholarly journals Two Unrelated 8-Vinyl Reductases Ensure Production of Mature Chlorophylls in Acaryochloris marina

2016 ◽  
Vol 198 (9) ◽  
pp. 1393-1400 ◽  
Author(s):  
Guangyu E. Chen ◽  
Andrew Hitchcock ◽  
Philip J. Jackson ◽  
Roy R. Chaudhuri ◽  
Mark J. Dickman ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
High Sequence Similarity ◽  
Content Type ◽  
Ethyl Group ◽  
Acaryochloris Marina ◽  
Vinyl Group ◽  
Vinyl Reductase ◽  
Reading Frames

ABSTRACTThe major photopigment of the cyanobacteriumAcaryochloris marinais chlorophylld, while its direct biosynthetic precursor, chlorophylla, is also present in the cell. These pigments, along with the majority of chlorophylls utilized by oxygenic phototrophs, carry an ethyl group at the C-8 position of the molecule, having undergone reduction of a vinyl group during biosynthesis. Two unrelated classes of 8-vinyl reductase involved in the biosynthesis of chlorophylls are known to exist, BciA and BciB. The genome ofAcaryochloris marinacontains open reading frames (ORFs) encoding proteins displaying high sequence similarity to BciA or BciB, although they are annotated as genes involved in transcriptional control (nmrA) and methanogenesis (frhB), respectively. These genes were introduced into an 8-vinyl chlorophylla-producing ΔbciBstrain ofSynechocystissp. strain PCC 6803, and both were shown to restore synthesis of the pigment with an ethyl group at C-8, demonstrating their activities as 8-vinyl reductases. We propose thatnmrAandfrhBbe reassigned asbciAandbciB, respectively; transcript and proteomic analysis ofAcaryochloris marinareveal that bothbciAandbciBare expressed and their encoded proteins are present in the cell, possibly in order to ensure that all synthesized chlorophyll pigment carries an ethyl group at C-8. Potential reasons for the presence of two 8-vinyl reductases in this strain, which is unique for cyanobacteria, are discussed.IMPORTANCEThe cyanobacteriumAcaryochloris marinais the best-studied phototrophic organism that uses chlorophylldfor photosynthesis. Unique among cyanobacteria sequenced to date, its genome contains ORFs encoding two unrelated enzymes that catalyze the reduction of the C-8 vinyl group of a precursor molecule to an ethyl group. Carrying a reduced C-8 group may be of particular importance to organisms containing chlorophylld. Plant genomes also contain orthologs of both of these genes; thus, the bacterial progenitor of the chloroplast may also have contained bothbciAandbciB.

scholarly journals Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov., moderately halophilic bacteria isolated from a deep-sea methane cold seep

2007 ◽  
Vol 57 (6) ◽  
pp. 1243-1249 ◽  
Author(s):  
Ngoc-Phuc Hua ◽  
Atsuko Kanekiyo ◽  
Katsunori Fujikura ◽  
Hisato Yasuda ◽  
Takeshi Naganuma
Keyword(s):  
Deep Sea ◽  
Sequence Similarity ◽  
Halophilic Bacteria ◽  
Cold Seep ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
High Sequence Similarity ◽  
Moderately Halophilic ◽  
Type Strains ◽  
Moderately Halophilic Bacteria

Two Gram-positive, rod-shaped, moderately halophilic bacteria were isolated from a deep-sea carbonate rock at a methane cold seep in Kuroshima Knoll, Japan. These bacteria, strains IS-Hb4T and IS-Hb7T, were spore-forming and non-motile. They were able to grow at temperatures as low as 9 °C and hydrostatic pressures up to 30 MPa. Based on high sequence similarity of their 16S rRNA genes to those of type strains of the genus Halobacillus, from 96.4 % (strain IS-Hb7T to Halobacillus halophilus NCIMB 9251T) to 99.4 % (strain IS-Hb4T to Halobacillus dabanensis D-8T), the strains were shown to belong to this genus. DNA–DNA relatedness values of 49.5 % and 1.0–33.0 %, respectively, were determined between strains IS-Hb4T and IS-Hb7T and between these strains and other Halobacillus type strains. Both strains showed the major menaquinone MK7 and l-orn–d-Asp cell-wall peptidoglycan type. Straight-chain C16 : 0, unsaturated C16 : 1 ω7c alcohol and C18 : 1 ω7c and cyclopropane C19 : 0 cyc fatty acids were predominant in both strains. The DNA G+C contents of IS-Hb4T and IS-Hb7T were respectively 43.3 and 42.1 mol%. Physiological and biochemical analyses combined with DNA–DNA hybridization results allowed us to place strains IS-Hb4T (=JCM 14154T=DSM 18394T) and IS-Hb7T (=JCM 14155T=DSM 18393T) in the genus Halobacillus as the respective type strains of the novel species Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov.

scholarly journals The embryonic RNA helicase gene (ERH): a new member of the DEAD box family of RNA helicases

1995 ◽  
Vol 308 (3) ◽  
pp. 839-846 ◽  
Author(s):  
J Sowden ◽  
W Putt ◽  
K Morrison ◽  
R Beddington ◽  
Y Edwards
Keyword(s):  
Expression Profile ◽  
Sequence Similarity ◽  
Rna Helicase ◽  
Chromosome 1 ◽  
Rna Helicases ◽  
High Sequence Similarity ◽  
Dead Box ◽  
Isolation And Characterization ◽  
Helicase Gene ◽  
The Dead

DEAD box proteins share several highly conserved motifs including the characteristic Asp-Glu-Ala-Asp (D-E-A-D in the amino acid single-letter code) motif and have established or putative ATP-dependent RNA helicase activity. These proteins are implicated in a range of cellular processes that involve regulation of RNA function, including translation initiation, RNA splicing and ribosome assembly. Here we describe the isolation and characterization of an embryonic RNA helicase gene, ERH, which maps to mouse chromosome 1 and encodes a new member of the DEAD box family of proteins. The predicted ERH protein shows high sequence similarity to the testes-specific mouse PL10 and to the maternally acting Xenopus An3 helicase proteins. The ERH expression profile is similar, to that of An3, which localizes to the animal hemisphere of oocytes and is abundantly expressed in the embryo. ERH is expressed in oocytes and is a ubiquitous mRNA in the 9 days-post-conception embryo, and at later stages of development shows a more restricted pattern of expression in brain and kidney. The similarities in sequence and in expression profile suggest that ERH is the murine equivalent of the Xenopus An3 gene, and we propose that ERH plays a role in translational activation of mRNA in the oocyte and early embryo.

Evolutionary rewiring of the wheat transcriptional regulatory network by lineage-specific transposable elements

2021 ◽  
pp. gr.275658.121
Author(s):  
Yuyun Zhang ◽  
Zijuan Li ◽  
Yu'e Zhang ◽  
Kande Lin ◽  
Yuan Peng ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Genome Evolution ◽  
Regulatory Networks ◽  
Transcriptional Regulatory Network ◽  
Sequence Similarity ◽  
Purifying Selection ◽  
Wheat Genome ◽  
Specific Gene ◽  
High Sequence Similarity ◽  
Wheat Genome Evolution

More than 80% of the wheat genome consists of transposable elements (TEs), which act as one major driver of wheat genome evolution. However, their contributions to the regulatory evolution of wheat adaptations remain largely unclear. Here, we created genome-binding maps for 53 transcription factors (TFs) underlying environmental responses by leveraging DAP-seq in Triticum urartu, together with epigenomic profiles. Most TF-binding sites (TFBS) located distally from genes are embedded in TEs, whose functional relevance is supported by purifying selection and active epigenomic features. About 24% of the non-TE TFBS share significantly high sequence similarity with TE-embedded TFBS. These non-TE TFBS have almost no homologous sequences in non-Triticeae species and are potentially derived from Triticeae-specific TEs. The expansion of TE-derived TFBS linked to wheat-specific gene responses, suggesting TEs are an important driving force for regulatory innovations. Altogether, TEs have been significantly and continuously shaping regulatory networks related to wheat genome evolution and adaptation.

scholarly journals Cloning and Characterization of R3b; Members of the R3 Superfamily of Late Blight Resistance Genes Show Sequence and Functional Divergence

2011 ◽  
Vol 24 (10) ◽  
pp. 1132-1142 ◽  
Author(s):  
Guangcun Li ◽  
Sanwen Huang ◽  
Xiao Guo ◽  
Ying Li ◽  
Yu Yang ◽  
...  
Keyword(s):  
Late Blight ◽  
Positional Cloning ◽  
Sequence Similarity ◽  
Functional Divergence ◽  
Durable Resistance ◽  
Coiled Coil ◽  
Avirulence Gene ◽  
R Gene ◽  
Gene Stacking ◽  
High Sequence Similarity

Massive resistance (R) gene stacking is considered to be one of the most promising approaches to provide durable resistance to potato late blight for both conventional and genetically modified breeding strategies. The R3 complex locus on chromosome XI in potato is an example of natural R gene stacking, because it contains two closely linked R genes (R3a and R3b) with distinct resistance specificities to Phytophthora infestans. Here, we report about the positional cloning of R3b. Both transient and stable transformations of susceptible tobacco and potato plants showed that R3b conferred full resistance to incompatible P. infestans isolates. R3b encodes a coiled-coil nucleotide-binding site leucine-rich repeat protein and exhibits 82% nucleotide identity with R3a located in the same R3 cluster. The R3b gene specifically recognizes Avr3b, a newly identified avirulence factor from P. infestans. R3b does not recognize Avr3a, the corresponding avirulence gene for R3a, showing that, despite their high sequence similarity, R3b and R3a have clearly distinct recognition specificities. In addition to the Rpi-mcd1/Rpi-blb3 locus on chromosome IV, the R3 locus on chromosome XI is the second example of an R-gene cluster with multiple genes recognizing different races of P. infestans.

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