Diversity and sequence motifs of the bacterial SecA protein motor

Background: Although most nucleotides in the genome form canonical double-stranded B-DNA, many repeated sequences transiently present as non-canonical conformations (non-B DNA) such as triplexes, quadruplexes, Z-DNA, cruciforms, and slipped/hairpins. Those noncanonical DNAs (ncDNAs) are not only associated with many genetic events such as replication, transcription, and recombination, but are also related to the genetic instability that results in the predisposition to disease. Due to the crucial roles of ncDNAs in cellular and genetic functions, various computational methods have been implemented to predict sequence motifs that generate ncDNA. Objective: Here, we review strategies for the identification of ncDNA motifs across the whole genome, which is necessary for further understanding and investigation of the structure and function of ncDNAs. Conclusion: There is a great demand for computational prediction of non-canonical DNAs that play key functional roles in gene expression and genome biology. In this study, we review the currently available computational methods for predicting the non-canonical DNAs in the genome. Current studies not only provide an insight into the computational methods for predicting the secondary structures of DNA but also increase our understanding of the roles of non-canonical DNA in the genome.

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Analysis of the Genetic Variability of Virulence-Related Loci in Epidemic Clones of Methicillin-Resistant Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.1.366-379.2005 ◽

2005 ◽

Vol 49 (1) ◽

pp. 366-379 ◽

Cited By ~ 41

Author(s):

A. R. Gomes ◽

S. Vinga ◽

M. Zavolan ◽

H. de Lencastre

Keyword(s):

Staphylococcus Aureus ◽

Genetic Variability ◽

Amino Acid Level ◽

Point Of View ◽

Sequence Motifs ◽

Related Factors ◽

Specific Sequence ◽

Methicillin Resistant ◽

Sequence Types ◽

R Domain

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) isolates have previously been classified into major epidemic clonal types by pulsed-field gel electrophoresis in combination with multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec typing. We aimed to investigate whether genetic variability in potentially polymorphic domains of virulence-related factors could provide another level of differentiation in a diverse collection of epidemic MRSA clones. The target regions of strains representative of epidemic clones and genetically related methicillin-susceptible S. aureus isolates from the 1960s that were sequenced included the R domains of clfA and clfB; the D, W, and M regions of fnbA and fnbB; and three regions in the agr operon. Sequence variation ranged from very conserved regions, such as those for RNAIII and the agr interpromoter region, to the highly polymorphic R regions of the clf genes. The sequences of the clf R domains could be grouped into six major sequence types on the basis of the sequences in their 3′ regions. Six sequence types were also observed for the fnb sequences at the amino acid level. From an evolutionary point of view, it was interesting that a small DNA stretch at the 3′ clf R-domain sequence and the fnb sequences agreed with the results of MLST for this set of strains. In particular, clfB R-domain sequences, which had a high discriminatory capacity and with which the types distinguished were congruent with those obtained by other molecular typing methods, have potential for use for the typing of S. aureus. Clone- and strain-specific sequence motifs in the clf and fnb genes may represent useful additions to a typing methodology with a DNA array.

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DNABERT: pre-trained Bidirectional Encoder Representations from Transformers model for DNA-language in genome

Bioinformatics ◽

10.1093/bioinformatics/btab083 ◽

2021 ◽

Author(s):

Yanrong Ji ◽

Zhihan Zhou ◽

Han Liu ◽

Ramana V Davuluri

Keyword(s):

Dna Sequences ◽

Regulatory Elements ◽

Ease Of Use ◽

Fine Tuning ◽

Supplementary Information ◽

Sequence Motifs ◽

Semantic Relationship ◽

Accurate Identification ◽

Conserved Sequence ◽

Genome Wide

Abstract Motivation Deciphering the language of non-coding DNA is one of the fundamental problems in genome research. Gene regulatory code is highly complex due to the existence of polysemy and distant semantic relationship, which previous informatics methods often fail to capture especially in data-scarce scenarios. Results To address this challenge, we developed a novel pre-trained bidirectional encoder representation, named DNABERT, to capture global and transferrable understanding of genomic DNA sequences based on up and downstream nucleotide contexts. We compared DNABERT to the most widely used programs for genome-wide regulatory elements prediction and demonstrate its ease of use, accuracy and efficiency. We show that the single pre-trained transformers model can simultaneously achieve state-of-the-art performance on prediction of promoters, splice sites and transcription factor binding sites, after easy fine-tuning using small task-specific labeled data. Further, DNABERT enables direct visualization of nucleotide-level importance and semantic relationship within input sequences for better interpretability and accurate identification of conserved sequence motifs and functional genetic variant candidates. Finally, we demonstrate that pre-trained DNABERT with human genome can even be readily applied to other organisms with exceptional performance. We anticipate that the pre-trained DNABERT model can be fined tuned to many other sequence analyses tasks. Availability and implementation The source code, pretrained and finetuned model for DNABERT are available at GitHub (https://github.com/jerryji1993/DNABERT). Supplementary information Supplementary data are available at Bioinformatics online.

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A Comprehensive Phylogenetic and Bioinformatics Survey of Lectins in the Fungal Kingdom

Journal of Fungi ◽

10.3390/jof7060453 ◽

2021 ◽

Vol 7 (6) ◽

pp. 453

Author(s):

Annie Lebreton ◽

François Bonnardel ◽

Yu-Cheng Dai ◽

Anne Imberty ◽

Francis M. Martin ◽

...

Keyword(s):

Evolutionary Relationship ◽

Large Family ◽

Gene Families ◽

Carbohydrate Binding ◽

Sequence Motifs ◽

Fungal Lectin ◽

Quaternary Structures ◽

High Degree ◽

Carbohydrate Ligand ◽

Fungal Kingdom

Fungal lectins are a large family of carbohydrate-binding proteins with no enzymatic activity. They play fundamental biological roles in the interactions of fungi with their environment and are found in many different species across the fungal kingdom. In particular, their contribution to defense against feeders has been emphasized, and when secreted, lectins may be involved in the recognition of bacteria, fungal competitors and specific host plants. Carbohydrate specificities and quaternary structures vary widely, but evidence for an evolutionary relationship within the different classes of fungal lectins is supported by a high degree of amino acid sequence identity. The UniLectin3D database contains 194 fungal lectin 3D structures, of which 129 are characterized with a carbohydrate ligand. Using the UniLectin3D lectin classification system, 109 lectin sequence motifs were defined to screen 1223 species deposited in the genomic portal MycoCosm of the Joint Genome Institute. The resulting 33,485 putative lectin sequences are organized in MycoLec, a publicly available and searchable database. These results shed light on the evolution of the lectin gene families in fungi.

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Context-specific action of macrolide antibiotics on the eukaryotic ribosome

Nature Communications ◽

10.1038/s41467-021-23068-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Maxim S. Svetlov ◽

Timm O. Koller ◽

Sezen Meydan ◽

Vaishnavi Shankar ◽

Dorota Klepacki ◽

...

Keyword(s):

Amino Acid Sequences ◽

Macrolide Antibiotics ◽

Single Mutation ◽

Sequence Motifs ◽

Eukaryotic Translation ◽

Eukaryotic Ribosome ◽

Cellular Translation ◽

Distinct Sequence ◽

Exit Tunnel ◽

Context Specific

AbstractMacrolide antibiotics bind in the nascent peptide exit tunnel of the bacterial ribosome and prevent polymerization of specific amino acid sequences, selectively inhibiting translation of a subset of proteins. Because preventing translation of individual proteins could be beneficial for the treatment of human diseases, we asked whether macrolides, if bound to the eukaryotic ribosome, would retain their context- and protein-specific action. By introducing a single mutation in rRNA, we rendered yeast Saccharomyces cerevisiae cells sensitive to macrolides. Cryo-EM structural analysis showed that the macrolide telithromycin binds in the tunnel of the engineered eukaryotic ribosome. Genome-wide analysis of cellular translation and biochemical studies demonstrated that the drug inhibits eukaryotic translation by preferentially stalling ribosomes at distinct sequence motifs. Context-specific action markedly depends on the macrolide structure. Eliminating macrolide-arrest motifs from a protein renders its translation macrolide-tolerant. Our data illuminate the prospects of adapting macrolides for protein-selective translation inhibition in eukaryotic cells.

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Structural and mechanistic basis for translation inhibition by macrolide and ketolide antibiotics

Nature Communications ◽

10.1038/s41467-021-24674-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Bertrand Beckert ◽

Elodie C. Leroy ◽

Shanmugapriya Sothiselvam ◽

Lars V. Bock ◽

Maxim S. Svetlov ◽

...

Keyword(s):

Antibiotic Resistance Genes ◽

Structural Basis ◽

Sequence Motifs ◽

Specific Sequence ◽

Bacterial Ribosome ◽

Translational Arrest ◽

Exit Tunnel ◽

Mechanistic Basis ◽

Dynamics Simulations ◽

Context Specific

AbstractMacrolides and ketolides comprise a family of clinically important antibiotics that inhibit protein synthesis by binding within the exit tunnel of the bacterial ribosome. While these antibiotics are known to interrupt translation at specific sequence motifs, with ketolides predominantly stalling at Arg/Lys-X-Arg/Lys motifs and macrolides displaying a broader specificity, a structural basis for their context-specific action has been lacking. Here, we present structures of ribosomes arrested during the synthesis of an Arg-Leu-Arg sequence by the macrolide erythromycin (ERY) and the ketolide telithromycin (TEL). Together with deep mutagenesis and molecular dynamics simulations, the structures reveal how ERY and TEL interplay with the Arg-Leu-Arg motif to induce translational arrest and illuminate the basis for the less stringent sequence-specific action of ERY over TEL. Because programmed stalling at the Arg/Lys-X-Arg/Lys motifs is used to activate expression of antibiotic resistance genes, our study also provides important insights for future development of improved macrolide antibiotics.

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Evidence for a Role for AtMYB2 in the Induction of the Arabidopsis Alcohol Dehydrogenase Gene (ADH1) by Low Oxygen

Genetics ◽

10.1093/genetics/149.2.479 ◽

1998 ◽

Vol 149 (2) ◽

pp. 479-490

Author(s):

Frank U Hoeren ◽

Rudy Dolferus ◽

Yingru Wu ◽

W James Peacock ◽

Elizabeth S Dennis

Keyword(s):

Transgenic Arabidopsis ◽

Nicotiana Plumbaginifolia ◽

Constitutive Promoter ◽

Sequence Motifs ◽

Regulatory Factor ◽

Low Oxygen ◽

Transient Assays ◽

Adh1 Gene ◽

Dehydrogenase Gene ◽

Adh1 Promoter

Abstract The transcription factor AtMYB2 binds to two sequence motifs in the promoter of the Arabidopsis ADH1 gene. The binding to the GT-motif (5′-TGGTTT-3′) is essential for induction of ADH1 by low oxygen, while binding to the second motif, MBS-2, is not essential for induction. We show that AtMYB2 is induced by hypoxia with kinetics compatible with a role in the regulation of ADH1. Like ADH1, AtMYB2 has root-limited expression. When driven by a constitutive promoter, AtMYB2 is able to transactivate ADH1 expression in transient assays in both Arabidopsis and Nicotiana plumbaginifolia protoplasts, and in particle bombardment of Pisum sativum leaves. Mutation of the GT-motif abolished binding of AtMYB2 and caused loss of activity of the ADH1 promoter in both transient assays and transgenic Arabidopsis plants. These results are consistent with AtMYB2 being a key regulatory factor in the induction of the ADH1 promoter by low oxygen.

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Olfactory expression of trace amine-associated receptors requires cooperative cis-acting enhancers

Nature Communications ◽

10.1038/s41467-021-23824-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ami Shah ◽

Madison Ratkowski ◽

Alessandro Rosa ◽

Paul Feinstein ◽

Thomas Bozza

Keyword(s):

Gene Expression ◽

Large Family ◽

Sequence Motifs ◽

Specific Expression ◽

Cis Acting ◽

Conserved Sequence ◽

Trace Amine ◽

Sequence Elements ◽

Cell Type Specific Expression ◽

Cell Type Specific

AbstractOlfactory sensory neurons express a large family of odorant receptors (ORs) and a small family of trace amine-associated receptors (TAARs). While both families are subject to so-called singular expression (expression of one allele of one gene), the mechanisms underlying TAAR gene choice remain obscure. Here, we report the identification of two conserved sequence elements in the mouse TAAR cluster (T-elements) that are required for TAAR gene expression. We observed that cell-type-specific expression of a TAAR-derived transgene required either T-element. Moreover, deleting either element reduced or abolished expression of a subset of TAAR genes, while deleting both elements abolished olfactory expression of all TAARs in cis with the mutation. The T-elements exhibit several features of known OR enhancers but also contain highly conserved, unique sequence motifs. Our data demonstrate that TAAR gene expression requires two cooperative cis-acting enhancers and suggest that ORs and TAARs share similar mechanisms of singular expression.

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Antimutator mutations in the alpha subunit of Escherichia coli DNA polymerase III: identification of the responsible mutations and alignment with other DNA polymerases.

Genetics ◽

10.1093/genetics/134.4.1039 ◽

1993 ◽

Vol 134 (4) ◽

pp. 1039-1044 ◽

Cited By ~ 2

Author(s):

I J Fijalkowska ◽

R M Schaaper

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Dna Polymerase ◽

Dna Polymerases ◽

Alpha Subunit ◽

Sequence Motifs ◽

Dna Polymerase Iii ◽

Conserved Sequence ◽

Polymerase Iii ◽

Dna Replication Errors

Abstract The dnaE gene of Escherichia coli encodes the DNA polymerase (alpha subunit) of the main replicative enzyme, DNA polymerase III holoenzyme. We have previously identified this gene as the site of a series of seven antimutator mutations that specifically decrease the level of DNA replication errors. Here we report the nucleotide sequence changes in each of the different antimutator dnaE alleles. For each a single, but different, amino acid substitution was found among the 1,160 amino acids of the protein. The observed substitutions are generally nonconservative. All affected residues are located in the central one-third of the protein. Some insight into the function of the regions of polymerase III containing the affected residues was obtained by amino acid alignment with other DNA polymerases. We followed the principles developed in 1990 by M. Delarue et al. who have identified in DNA polymerases from a large number of prokaryotic and eukaryotic sources three highly conserved sequence motifs, which are suggested to contain components of the polymerase active site. We succeeded in finding these three conserved motifs in polymerase III as well. However, none of the amino acid substitutions responsible for the antimutator phenotype occurred at these sites. This and other observations suggest that the effect of these mutations may be exerted indirectly through effects on polymerase conformation and/or DNA/polymerase interactions.

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