scholarly journals Distribution of sequence-dependent curvature in genomic DNA sequences

FEBS Letters ◽  
1997 ◽  
Vol 406 (1-2) ◽  
pp. 69-74 ◽  
Author(s):  
Andrei Gabrielian ◽  
Kristian Vlahovicek ◽  
Sándor Pongor
Author(s):  
Kuldeepsingh A. Kalariya ◽  
Ram Prasnna Meena ◽  
Lipi Poojara ◽  
Deepa Shahi ◽  
Sandip Patel

Abstract Background Squalene synthase (SQS) is a rate-limiting enzyme necessary to produce pentacyclic triterpenes in plants. It is an important enzyme producing squalene molecules required to run steroidal and triterpenoid biosynthesis pathways working in competitive inhibition mode. Reports are available on information pertaining to SQS gene in several plants, but detailed information on SQS gene in Gymnema sylvestre R. Br. is not available. G. sylvestre is a priceless rare vine of central eco-region known for its medicinally important triterpenoids. Our work aims to characterize the GS-SQS gene in this high-value medicinal plant. Results Coding DNA sequences (CDS) with 1245 bp length representing GS-SQS gene predicted from transcriptome data in G. sylvestre was used for further characterization. The SWISS protein structure modeled for the GS-SQS amino acid sequence data had MolProbity Score of 1.44 and the Clash Score 3.86. The quality estimates and statistical score of Ramachandran plots analysis indicated that the homology model was reliable. For full-length amplification of the gene, primers designed from flanking regions of CDS encoding GS-SQS were used to get amplification against genomic DNA as template which resulted in approximately 6.2-kb sized single-band product. The sequencing of this product through NGS was carried out generating 2.32 Gb data and 3347 number of scaffolds with N50 value of 457 bp. These scaffolds were compared to identify similarity with other SQS genes as well as the GS-SQSs of the transcriptome. Scaffold_3347 representing the GS-SQS gene harbored two introns of 101 and 164 bp size. Both these intronic regions were validated by primers designed from adjoining outside regions of the introns on the scaffold representing GS-SQS gene. The amplification took place when the template was genomic DNA and failed when the template was cDNA confirmed the presence of two introns in GS-SQS gene in Gymnema sylvestre R. Br. Conclusion This study shows GS-SQS gene was very closely related to Coffea arabica and Gardenia jasminoides and this gene harbored two introns of 101 and 164 bp size.


Yeast ◽  
1997 ◽  
Vol 13 (3) ◽  
pp. 233-240 ◽  
Author(s):  
KRISTIN T. CHUN ◽  
HOWARD J. EDENBERG ◽  
MARK R. KELLEY ◽  
MARK G. GOEBL

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2748 ◽  
Author(s):  
Ae-Ree Lee ◽  
Na-Hyun Kim ◽  
Yeo-Jin Seo ◽  
Seo-Ree Choi ◽  
Joon-Hwa Lee

Z-DNA is stabilized by various Z-DNA binding proteins (ZBPs) that play important roles in RNA editing, innate immune response, and viral infection. In this review, the structural and dynamics of various ZBPs complexed with Z-DNA are summarized to better understand the mechanisms by which ZBPs selectively recognize d(CG)-repeat DNA sequences in genomic DNA and efficiently convert them to left-handed Z-DNA to achieve their biological function. The intermolecular interaction of ZBPs with Z-DNA strands is mediated through a single continuous recognition surface which consists of an α3 helix and a β-hairpin. In the ZBP-Z-DNA complexes, three identical, conserved residues (N173, Y177, and W195 in the Zα domain of human ADAR1) play central roles in the interaction with Z-DNA. ZBPs convert a 6-base DNA pair to a Z-form helix via the B-Z transition mechanism in which the ZBP first binds to B-DNA and then shifts the equilibrium from B-DNA to Z-DNA, a conformation that is then selectively stabilized by the additional binding of a second ZBP molecule. During B-Z transition, ZBPs selectively recognize the alternating d(CG)n sequence and convert it to a Z-form helix in long genomic DNA through multiple sequence discrimination steps. In addition, the intermediate complex formed by ZBPs and B-DNA, which is modulated by varying conditions, determines the degree of B-Z transition.


1992 ◽  
Vol 20 (21) ◽  
pp. 5842-5842
Author(s):  
Joonho Sheen ◽  
Seungmoak Kim ◽  
Yung Hee Kho ◽  
Kyung Sook Bae

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 716-728 ◽  
Author(s):  
Pavel Neumann ◽  
Marcela Nouzová ◽  
Jirí Macas

A set of pea DNA sequences representing the most abundant genomic repeats was obtained by combining several approaches. Dispersed repeats were isolated by screening a short-insert genomic library using genomic DNA as a probe. Thirty-two clones ranging from 149 to 2961 bp in size and from 1000 to 39 000/1C in their copy number were sequenced and further characterized. Fourteen clones were identified as retrotransposon-like sequences, based on their homologies to known elements. Fluorescence in situ hybridization using clones of reverse transcriptase and integrase coding sequences as probes revealed that corresponding retroelements were scattered along all pea chromosomes. Two novel families of tandem repeats, named PisTR-A and PisTR-B, were isolated by screening a genomic DNA library with Cot-1 DNA and by employing genomic self-priming PCR, respectively. PisTR-A repeats are 211–212 bp long, their abundance is 2 × 104 copies/1C, and they are partially clustered in a secondary constriction of one chromosome pair with the rest of their copies dispersed on all chromosomes. PisTR-B sequences are of similar abundance (104 copies/1C) but differ from the "A" family in their monomer length (50 bp), high A/T content, and chromosomal localization in a limited number of discrete bands. These bands are located mainly in (sub)telomeric and pericentromeric regions, and their patterns, together with chromosome morphology, allow discrimination of all chromosome types within the pea karyotype. Whereas both tandem repeat families are mostly specific to the genus Pisum, many of the dispersed repeats were detected in other legume species, mainly those in the genus Vicia.Key words: repetitive DNA, plant genome, retroelements, satellite DNA, Pisum sativum.


Plant Science ◽  
1996 ◽  
Vol 117 (1-2) ◽  
pp. 121-129 ◽  
Author(s):  
U. Malkamäki ◽  
M.S. Clark ◽  
H. Rita ◽  
J.P.T. Valkonen ◽  
E. Pehu

2005 ◽  
Vol 51 (12) ◽  
pp. 1045-1055 ◽  
Author(s):  
Zhen-Xiang Lu ◽  
André Laroche ◽  
Hung Chang Huang

Degenerate PCR primers corresponding to conserved domains of fungal chitinases were designed, and PCR was performed on genomic DNA of the entomogenous fungus Verticillium lecanii (Zimmermann) Viegas. Two distinct PCR fragments, chf1 and chf2, were isolated and used to identify two DNA contigs. Analyses of these two contigs revealed that we had obtained the full-length DNA sequence including the promoter, 5′ untranslated region, open reading frame (ORF), and 3′ untranslated regions for two distinct chitinase-like genes. These two genomic DNA sequences exhibited 51% identity at the amino acid (aa) level and were designed as acidic (chi1) and basic (chi2) chitinase-like genes. The isolated cDNA for chi1 gene is 1110 bp with a predicted protein of 370 aa and molecular mass of 40.93 kDa, and its ORF was uninterrupted in its corresponding genomic DNA sequence. The cDNA for the chi2 gene is 1269 bp, a predicted ORF of 423 aa and molecular mass of 45.95 kDa. In contrast, the ORF was interrupted by three introns in its corresponding genomic DNA. The basic chitinase gene (chi2) was successfully expressed in the Pichia pastoris system; optimum enzymatic activity was observed at 22 °C and at pH 7.5. CHI1 and CHI2 were clustered into two different phylogenetic groups according to their sequence alignments with 28 other fungal chitinases. A chitin-binding domain, comprising two sub-domains that exhibit similarities at the aa level to chitin binding domains in bacteria, was identified in 30 fungal chitinase sequences examined.Key words: fungus, chitin, cloning, sequencing, transformation, Pichia sp. expression.


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