pH-Modulated Watson–Crick Duplex–Quadruplex Equilibria of Guanine-Rich and Cytosine-Rich DNA Sequences 140 Base Pairs Upstream of thec-kitTranscription Initiation Site

2009 ◽  
Vol 15 (46) ◽  
pp. 12663-12671 ◽  
Author(s):  
Pavel Bucek ◽  
Joaquim Jaumot ◽  
Anna Aviñó ◽  
Ramon Eritja ◽  
Raimundo Gargallo
Keyword(s):  
Dna Sequences ◽  
Initiation Site ◽  
Base Pairs

scholarly journals Sequences involved in temperature and ecdysterone-induced transcription are located in separate regions of a Drosophila melanogaster heat shock gene.

1986 ◽  
Vol 6 (2) ◽  
pp. 663-673 ◽  
Author(s):  
E Hoffman ◽  
V Corces
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Dna Sequences ◽  
Germ Line ◽  
Initiation Site ◽  
P Element ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Consensus Sequences ◽  
Shock Gene

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.

scholarly journals New Code for DNA Nucleotide Sequences

2020 ◽  
Author(s):  
Charles Schaper
Keyword(s):  
Hydrogen Bonds ◽  
Gene Transcription ◽  
Dna Sequences ◽  
Structural Characteristics ◽  
Intermolecular Hydrogen Bond ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Nucleotide Sequences ◽  
Base Pairs ◽  
Ionic Binding

DNA nucleotides consist of the complementary base pairs of Adenine-Thymine (A-T) and Cytosine-Guanine (C-G) that encode as a sequence for genes, and encode for an upstream initiation site that enables transcription. Recently, this lab has shown that steroid hormones are structurally symmetric with each of the four DNA nucleotide pairs and through an ionic binding process may enable gene transcription. Here, a new code is developed for DNA nucleotide sequences that relates to the initiation site for gene transcription. The structural code consists of the orientation of steroid molecules in binding to DNA nucleotides and the class of steroid molecules that form an intermolecular hydrogen bond with an available functional group of Thymine. This later class thereby describes a steroid hormone-DNA nucleotide-ion complex with three hydrogen bonds for A-T and T-A, which thereby matches the three internal hydrogen bonds associated with C-G and G-C. The code consists of two binary vectors to characterize the four configurations of DNA nucleotides and is shown to be consistent with known regulatory elements of DNA sequences associated with gene transcription, including the TATA box and the E-Box, along with other promoters. In addition, the code, which is bijective, is applied to analyze the DNA sequence associated with SARS-CoV-2 to identify regions with relevant structural characteristics.

Sequences involved in temperature and ecdysterone-induced transcription are located in separate regions of a Drosophila melanogaster heat shock gene

1986 ◽  
Vol 6 (2) ◽  
pp. 663-673
Author(s):  
E Hoffman ◽  
V Corces
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Dna Sequences ◽  
Germ Line ◽  
Initiation Site ◽  
P Element ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Consensus Sequences ◽  
Shock Gene

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.

scholarly journals New Code for DNA Nucleotide Sequences

2020 ◽  
Author(s):  
Charles Schaper
Keyword(s):  
Hydrogen Bonds ◽  
Gene Transcription ◽  
Dna Sequences ◽  
Structural Characteristics ◽  
Intermolecular Hydrogen Bond ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Nucleotide Sequences ◽  
Base Pairs ◽  
Ionic Binding

DNA nucleotides consist of the complementary base pairs of Adenine-Thymine (A-T) and Cytosine-Guanine (C-G) that encode as a sequence for genes, and encode for an upstream initiation site that enables transcription. Recently, this lab has shown that steroid hormones are structurally symmetric with each of the four DNA nucleotide pairs and through an ionic binding process may enable gene transcription. Here, a new code is developed for DNA nucleotide sequences that relates to the initiation site for gene transcription. The structural code consists of the orientation of steroid molecules in binding to DNA nucleotides and the class of steroid molecules that form an intermolecular hydrogen bond with an available functional group of Thymine. This later class thereby describes a steroid hormone-DNA nucleotide-ion complex with three hydrogen bonds for A-T and T-A, which thereby matches the three internal hydrogen bonds associated with C-G and G-C. The code consists of two binary vectors to characterize the four configurations of DNA nucleotides and is shown to be consistent with known regulatory elements of DNA sequences associated with gene transcription, including the TATA box and the E-Box, along with other promoters. In addition, the code, which is bijective, is applied to analyze the DNA sequence associated with SARS-CoV-2 to identify regions with relevant structural characteristics.

Developing a Genetic System in Deinococcus radiodurans for Analyzing Mutations

Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 661-668
Author(s):  
Mandy Kim ◽  
Erika Wolff ◽  
Tiffany Huang ◽  
Lilit Garibyan ◽  
Ashlee M Earl ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Deinococcus Radiodurans ◽  
Genetic System ◽  
Base Change ◽  
Base Substitution ◽  
Wild Type ◽  
Base Pairs ◽  
E Coli ◽  
Radiation Induced ◽  
Induced Mutagenesis

Abstract We have applied a genetic system for analyzing mutations in Escherichia coli to Deinococcus radiodurans, an extremeophile with an astonishingly high resistance to UV- and ionizing-radiation-induced mutagenesis. Taking advantage of the conservation of the β-subunit of RNA polymerase among most prokaryotes, we derived again in D. radiodurans the rpoB/Rif r system that we developed in E. coli to monitor base substitutions, defining 33 base change substitutions at 22 different base pairs. We sequenced >250 mutations leading to Rif r in D. radiodurans derived spontaneously in wild-type and uvrD (mismatch-repair-deficient) backgrounds and after treatment with N-methyl-N′-nitro-N-nitrosoguanidine (NTG) and 5-azacytidine (5AZ). The specificities of NTG and 5AZ in D. radiodurans are the same as those found for E. coli and other organisms. There are prominent base substitution hotspots in rpoB in both D. radiodurans and E. coli. In several cases these are at different points in each organism, even though the DNA sequences surrounding the hotspots and their corresponding sites are very similar in both D. radiodurans and E. coli. In one case the hotspots occur at the same site in both organisms.

scholarly journals THE DNA OF CAENORHABDITIS ELEGANS

Genetics ◽  
1974 ◽  
Vol 77 (1) ◽  
pp. 95-104
Author(s):  
J E Sulston ◽  
S Brenner
Keyword(s):  
Caenorhabditis Elegans ◽  
Chemical Analysis ◽  
Dna Sequences ◽  
Base Composition ◽  
Nematode Caenorhabditis Elegans ◽  
5S Rna ◽  
Base Pairs ◽  
Small Component ◽  
E Coli ◽  
The Mean

ABSTRACT Chemical analysis and a study of renaturation kinetics show that the nematode, Caenorhabditis elegans, has a haploid DNA content of 8 x IO7 base pairs (20 times the genome of E. coli). Eighty-three percent of the DNA sequences are unique. The mean base composition is 36% GC; a small component, containing the rRNA cistrons, has a base composition of 51% GC. The haploid genome contains about 300 genes for 4s RNA, 110 for 5s RNA, and 55 for (18 + 28)S RNA.

Transcriptional and posttranscriptional regulation of maize mitochondrial gene expression

1991 ◽  
Vol 11 (1) ◽  
pp. 533-543
Author(s):  
R M Mulligan ◽  
P Leon ◽  
V Walbot
Keyword(s):  
Dna Sequences ◽  
Transcription Initiation ◽  
Posttranscriptional Regulation ◽  
Rank Order ◽  
Mitochondrial Gene ◽  
Initiation Site ◽  
Gene Copy ◽  
Promoter Strength ◽  
Protein Coding

Lysed maize mitochondria synthesize RNA in the presence of radioactive nucleoside triphosphates, and this assay was utilized to compare the rates of transcription of seven genes. The rates of incorporation varied over a 14-fold range, with the following rank order: 18S rRNA greater than 26S rRNA greater than atp1 greater than atp6 greater than atp9 greater than cob greater than cox3. The products of run-on transcription hybridized specifically to known transcribed regions and selectively to the antisense DNA strand; thus, the isolated run-on transcription system appears to be an accurate representation of endogenous transcription. Although there were small differences in gene copy abundance, these differences cannot account for the differences in apparent transcription rates; we conclude that promoter strength is the main determinant. Among the protein coding genes, incorporation was greatest for atp1. The most active transcription initiation site of this gene was characterized by hybridization with in vitro-capped RNA and by primer extension analyses. The DNA sequences at this and other transcription initiation sites that we have previously mapped were analyzed with respect to the apparent promoter strengths. We propose that two short sequence elements just upstream of initiation sites form at least a portion of the sequence requirements for a maize mitochondrial promoter. In addition to modulation at the level of transcription, steady-state abundance of protein-coding mRNAs varied over a 20-fold range and did not correlate with transcriptional activity. These observations suggest that posttranscriptional processes are important in the modulation of mRNA abundance.

scholarly journals Theoretical modelling of epigenetically modified DNA sequences

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 52 ◽  
Author(s):  
Alexandra Teresa Pires Carvalho ◽  
Maria Leonor Gouveia ◽  
Charan Raju Kanna ◽  
Sebastian K. T. S. Wärmländer ◽  
Jamie Platts ◽  
...  
Keyword(s):  
Molecular Mechanics ◽  
Dna Sequences ◽  
Base Pair ◽  
Density Functional ◽  
Epigenetic Modifications ◽  
Theoretical Modelling ◽  
Sugar Phosphate ◽  
Base Pairs ◽  
Phosphate Backbone ◽  
Modified Dna

We report herein a set of calculations designed to examine the effects of epigenetic modifications on the structure of DNA. The incorporation of methyl, hydroxymethyl, formyl and carboxy substituents at the 5-position of cytosine is shown to hardly affect the geometry of CG base pairs, but to result in rather larger changes to hydrogen-bond and stacking binding energies, as predicted by dispersion-corrected density functional theory (DFT) methods. The same modifications within double-stranded GCG and ACA trimers exhibit rather larger structural effects, when including the sugar-phosphate backbone as well as sodium counterions and implicit aqueous solvation. In particular, changes are observed in the buckle and propeller angles within base pairs and the slide and roll values of base pair steps, but these leave the overall helical shape of DNA essentially intact. The structures so obtained are useful as a benchmark of faster methods, including molecular mechanics (MM) and hybrid quantum mechanics/molecular mechanics (QM/MM) methods. We show that previously developed MM parameters satisfactorily reproduce the trimer structures, as do QM/MM calculations which treat bases with dispersion-corrected DFT and the sugar-phosphate backbone with AMBER. The latter are improved by inclusion of all six bases in the QM region, since a truncated model including only the central CG base pair in the QM region is considerably further from the DFT structure. This QM/MM method is then applied to a set of double-stranded DNA heptamers derived from a recent X-ray crystallographic study, whose size puts a DFT study beyond our current computational resources. These data show that still larger structural changes are observed than in base pairs or trimers, leading us to conclude that it is important to model epigenetic modifications within realistic molecular contexts.

scholarly journals High frequency repeat-induced point mutation (RIP) is not associated with efficient recombination in Neurospora.

Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1093-1103 ◽  
Author(s):  
J T Irelan ◽  
A T Hagemann ◽  
E U Selker
Keyword(s):  
Point Mutation ◽  
Dna Sequences ◽  
High Frequency ◽  
Recombination Frequency ◽  
Single Copy ◽  
Sexual Cycle ◽  
Base Pairs ◽  
Copy Gene ◽  
The Relationship ◽  
Repeat Induced Point Mutation

Abstract Duplicated DNA sequences in Neurospora crassa are efficiently detected and mutated during the sexual cycle by a process named repeat-induced point mutation (RIP). Linked, direct duplications have previously been shown to undergo both RIP and deletion at high frequency during premeiosis, suggesting a relationship between RIP and homologous recombination. We have investigated the relationship between RIP and recombination for an unlinked duplication and for both inverted and direct, linked duplications. RIP occurred at high frequency (42-100%) with all three types of duplications used in this study, yet recombination was infrequent. For both inverted and direct, linked duplications, recombination was observed, but at frequencies one to two orders of magnitude lower than RIP. For the unlinked duplication, no recombinants were seen in 900 progeny, indicating, at most, a recombination frequency nearly three orders of magnitude lower than the frequency of RIP. In a direct duplication, RIP and recombination were correlated, suggesting that these two processes are mechanistically associated or that one process provokes the other. Mutations due to RIP have previously been shown to occur outside the boundary of a linked, direct duplication, indicating that RIP might be able to inactivate genes located in single-copy sequences adjacent to a duplicated sequence. In this study, a single-copy gene located between elements of linked duplications was inactivated at moderate frequencies (12-14%). Sequence analysis demonstrated that RIP mutations had spread into these single-copy sequences at least 930 base pairs from the boundary of the duplication, and Southern analysis indicated that mutations had occurred at least 4 kilobases from the duplication boundary.

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