scholarly journals The role of a minor groove spine of hydration in stabilizing poly(dA). poly(dT) against fuctuational interbase H-bond disruption in the premelting temperature regime

1992 ◽  
Vol 20 (3) ◽  
pp. 415-419 ◽  
Author(s):  
Y.Z. Chen ◽  
E. W. Prohofsky
Keyword(s):  
Temperature Regime ◽  
Minor Groove ◽  
A Minor ◽  
Bond Disruption

Comparison of the biological effects of MMS and Me-lex, a minor groove methylating agent: Clarifying the role of N3-methyladenine

2014 ◽  
Vol 759 ◽  
pp. 45-51 ◽  
Author(s):  
Paola Monti ◽  
Giorgia Foggetti ◽  
Paola Menichini ◽  
Alberto Inga ◽  
Barry Gold ◽  
...  
Keyword(s):  
Biological Effects ◽  
Minor Groove ◽  
A Minor

scholarly journals Efficient and Error-Free Replication Past a Minor-Groove DNA Adduct by the Sequential Action of Human DNA Polymerases ι and κ

2004 ◽  
Vol 24 (13) ◽  
pp. 5687-5693 ◽  
Author(s):  
M. Todd Washington ◽  
Irina G. Minko ◽  
Robert E. Johnson ◽  
William T. Wolfle ◽  
Thomas M. Harris ◽  
...  
Keyword(s):  
Dna Adducts ◽  
Dna Polymerases ◽  
Minor Groove ◽  
Dna Lesions ◽  
Initial Reaction ◽  
Dna Minor Groove ◽  
Nucleotide Incorporation ◽  
A Minor ◽  
Y Family

ABSTRACT DNA polymerase ι (Polι) is a member of the Y family of DNA polymerases, which promote replication through DNA lesions. The role of Polι in lesion bypass, however, has remained unclear. Polι is highly unusual in that it incorporates nucleotides opposite different template bases with very different efficiencies and fidelities. Since interactions of DNA polymerases with the DNA minor groove provide for the nearly equivalent efficiencies and fidelities of nucleotide incorporation opposite each of the four template bases, we considered the possibility that Polι differs from other DNA polymerases in not being as sensitive to distortions of the minor groove at the site of the incipient base pair and that this enables it to incorporate nucleotides opposite highly distorting minor-groove DNA adducts. To check the validity of this idea, we examined whether Polι could incorporate nucleotides opposite the γ-HOPdG adduct, which is formed from an initial reaction of acrolein with the N2 of guanine. We show here that Polι incorporates a C opposite this adduct with nearly the same efficiency as it does opposite a nonadducted template G residue. The subsequent extension step, however, is performed by Polκ, which efficiently extends from the C incorporated opposite the adduct. Based upon these observations, we suggest that an important biological role of Polι and Polκ is to act sequentially to carry out the efficient and accurate bypass of highly distorting minor-groove DNA adducts of the purine bases.

scholarly journals CarD uses a minor groove wedge mechanism to stabilize the RNA polymerase open promoter complex

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Brian Bae ◽  
James Chen ◽  
Elizabeth Davis ◽  
Katherine Leon ◽  
Seth A Darst ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Minor Groove ◽  
Initiation Complex ◽  
Regulate Gene Expression ◽  
E Coli ◽  
Transcription Bubble ◽  
Promoter Complex ◽  
Transcription Initiation Complex ◽  
A Minor

A key point to regulate gene expression is at transcription initiation, and activators play a major role. CarD, an essential activator in Mycobacterium tuberculosis, is found in many bacteria, including Thermus species, but absent in Escherichia coli. To delineate the molecular mechanism of CarD, we determined crystal structures of Thermus transcription initiation complexes containing CarD. The structures show CarD interacts with the unique DNA topology presented by the upstream double-stranded/single-stranded DNA junction of the transcription bubble. We confirm that our structures correspond to functional activation complexes, and extend our understanding of the role of a conserved CarD Trp residue that serves as a minor groove wedge, preventing collapse of the transcription bubble to stabilize the transcription initiation complex. Unlike E. coli RNAP, many bacterial RNAPs form unstable promoter complexes, explaining the need for CarD.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

THE ROLE OF ANTHROPONYMS IN THE SEMANTIC FIELD OF ARTISTIC WORKS

2019 ◽  
Vol 2019 (29) ◽  
pp. 66-77
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Literary Work ◽  
Main Theme ◽  
Semantic Field ◽  
New Meanings ◽  
Minor Part ◽  
The One ◽  
A Minor ◽  
And Storage ◽  
Horizon Of Expectations

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

scholarly journals Tcf4 Is Involved in Subset Specification of Mesodiencephalic Dopaminergic Neurons

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 317
Author(s):  
Simone Mesman ◽  
Iris Wever ◽  
Marten P. Smidt
Keyword(s):  
Neuronal Differentiation ◽  
Dopaminergic Neurons ◽  
Neuronal Development ◽  
Neuronal Population ◽  
Minor Role ◽  
Initial Increase ◽  
E Box ◽  
A Minor ◽  
Bhlh Factor

During development, mesodiencephalic dopaminergic (mdDA) neurons form into different molecular subsets. Knowledge of which factors contribute to the specification of these subsets is currently insufficient. In this study, we examined the role of Tcf4, a member of the E-box protein family, in mdDA neuronal development and subset specification. We show that Tcf4 is expressed throughout development, but is no longer detected in adult midbrain. Deletion of Tcf4 results in an initial increase in TH-expressing neurons at E11.5, but this normalizes at later embryonic stages. However, the caudal subset marker Nxph3 and rostral subset marker Ahd2 are affected at E14.5, indicating that Tcf4 is involved in correct differentiation of mdDA neuronal subsets. At P0, expression of these markers partially recovers, whereas expression of Th transcript and TH protein appears to be affected in lateral parts of the mdDA neuronal population. The initial increase in TH-expressing cells and delay in subset specification could be due to the increase in expression of the bHLH factor Ascl1, known for its role in mdDA neuronal differentiation, upon loss of Tcf4. Taken together, our data identified a minor role for Tcf4 in mdDA neuronal development and subset specification.

scholarly journals Plague and the Fall of Baghdad (1258)

2021 ◽  
Vol 65 (2) ◽  
pp. 157-177
Author(s):  
Nahyan Fancy ◽  
Monica H. Green
Keyword(s):  
Fourteenth Century ◽  
Thirteenth Century ◽  
Disease Outbreaks ◽  
Epidemic Disease ◽  
Late Medieval ◽  
Western Asia ◽  
Abbasid Caliphate ◽  
Historical Accounts ◽  
A Minor

AbstractThe recent suggestion that the late medieval Eurasian plague pandemic, the Black Death, had its origins in the thirteenth century rather than the fourteenth century has brought new scrutiny to texts reporting ‘epidemics’ in the earlier period. Evidence both from Song China and Iran suggests that plague was involved in major sieges laid by the Mongols between the 1210s and the 1250s, including the siege of Baghdad in 1258 which resulted in the fall of the Abbasid caliphate. In fact, re-examination of multiple historical accounts in the two centuries after the siege of Baghdad shows that the role of epidemic disease in the Mongol attacks was commonly known among chroniclers in Syria and Egypt, raising the question why these outbreaks have been overlooked in modern historiography of plague. The present study looks in detail at the evidence in Arabic sources for disease outbreaks after the siege of Baghdad in Iraq and its surrounding regions. We find subtle factors in the documentary record to explain why, even though plague received new scrutiny from physicians in the period, it remained a minor feature in stories about the Mongol invasion of western Asia. In contemporary understandings of the genesis of epidemics, the Mongols were not seen to have brought plague to Baghdad; they caused plague to arise by their rampant destruction. When an even bigger wave of plague struck the Islamic world in the fourteenth century, no association was made with the thirteenth-century episode. Rather, plague was now associated with the Mongol world as a whole.

The role of heredity in cancer.

1989 ◽  
Vol 7 (4) ◽  
pp. 527-540 ◽  
Author(s):  
E G Levine ◽  
R A King ◽  
C D Bloomfield
Keyword(s):  
Molecular Mechanisms ◽  
Familial Cancer ◽  
Tumor Development ◽  
Future Research ◽  
Minor Role ◽  
Research Activity ◽  
Environmental Interactions ◽  
Future Research Directions ◽  
A Minor

Heredity is generally felt to play a minor role in the development of cancer. This review critically examines this assumption. Topics discussed include evidence for heritable predisposition in animals and humans; the potential importance of genetic-environmental interactions; approaches that are being used to successfully locate genes responsible for heritable predisposition; comparability of genetic findings among heritable and corresponding sporadic malignancies; and future research directions. Breast, colon, and lung cancer are used to exemplify clinical and research activity in familial cancer; clinical phenotypes, segregation and linkage analyses, models for environmental interactions with inherited traits, and molecular mechanisms of tumor development are discussed. We conclude that the contribution of heredity to the cancer burden is greater than generally accepted, and that study of heritable predisposition will continue to reveal carcinogenic mechanisms important to the development of all cancers.

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