NMR Structures of r(GCAGGCGUGC)2and Determinants of Stability for Single Guanosine−Guanosine Base Pairs†,‡

Biochemistry ◽  
2000 ◽  
Vol 39 (38) ◽  
pp. 11748-11762 ◽  
Author(s):  
Mark E. Burkard ◽  
Douglas H. Turner
Keyword(s):  
Base Pairs ◽  
Nmr Structures

scholarly journals Reverse Watson-Crick purine-purine base pairs — the Sharp-turn motif and other structural consequences in functional RNAs

2017 ◽  
Author(s):  
Abhinav Mittal ◽  
Antarip Halder ◽  
Sohini Bhattacharya ◽  
Dhananjay Bhattacharyya ◽  
Abhijit Mitra
Keyword(s):  
Structural Alignment ◽  
Bimodal Distribution ◽  
Base Pairs ◽  
Purine Base ◽  
Functional Roles ◽  
Nmr Structures ◽  
Sharp Turn ◽  
Interesting Class ◽  
Functional Rnas ◽  
Noncanonical Base Pairs

AbstractIdentification of static and/or dynamic roles of different noncanonical base pairs is essential for a comprehensive understanding of the sequence-structure-function space of RNA. In this context, reverse Watson-Crick purine-purine base pairs (A:A, G:G&A:GW:W Trans) constitute an interesting class of noncanonical base pairs in RNA due to their characteristic C1′–C1′ distance (highest among all base pairing geometries) and parallel local strand orientation. Structural alignment of the RNA stretches containing these W:W Trans base pairs with their corresponding homologous sites in a non-redundant set of RNA crystal structures show that, as expected, these base pairs are associated with specific structural folds or functional roles. Detailed analysis of these contexts further revealed a bimodal distribution in the local backbone geometry parameters associated with these base pairs. One mode, populated by both A:A and G:G W:W Trans pairs, manifests itself as a characteristic backbone fold. We call this fold a ‘Sharp-turn’ motif. The other mode is exclusively associated with A:A W:W Trans pairs involved in mediating higher order interactions. The same trend is also observed in available solution NMR structures. We have also characterized the importance of recurrent hydrogen bonding interactions between adenine and guanine in W:W Trans geometry. Quantum chemical calculations performed at M05-2X/6-31++(2d,2p) level explain how the characteristic electronic properties of these W:W Trans base pairs facilitate their occurrence in such exclusive structural folds that are important for RNA functionalities.

Detection of the Glanzmann's Thrombasthenia Mutations in Arab and Iraqi-Jewish Patients by Polymerase Chain Reaction and Restriction Analysis of Blood or Urine Samples

1991 ◽  
Vol 66 (04) ◽  
pp. 500-504 ◽  
Author(s):  
H Peretz ◽  
U Seligsohn ◽  
E Zwang ◽  
B S Coller ◽  
P J Newman
Keyword(s):  
Polymerase Chain Reaction ◽  
Base Pair ◽  
Restriction Analysis ◽  
Urine Samples ◽  
Chain Reaction ◽  
Base Pairs ◽  
Glanzmann’S Thrombasthenia ◽  
Glanzmann's Thrombasthenia ◽  
Base Pair Deletion ◽  
Polymerase Chain

SummarySevere Glanzmann's thrombasthenia is relatively frequent in Iraqi-Jews and Arabs residing in Israel. We have recently described the mutations responsible for the disease in Iraqi-Jews – an 11 base pair deletion in exon 12 of the glycoprotein IIIa gene, and in Arabs – a 13 base pair deletion at the AG acceptor splice site of exon 4 on the glycoprotein IIb gene. In this communication we show that the Iraqi-Jewish mutation can be identified directly by polymerase chain reaction and gel electrophoresis. With specially designed oligonucleotide primers encompassing the mutation site, an 80 base pair segment amplified in healthy controls was clearly distinguished from the 69 base pair segment produced in patients. Patients from 11 unrelated Iraqi-Jewish families had the same mutation. The Arab mutation was identified by first amplifying a DNA segment consisting of 312 base pairs in controls and of 299 base pairs in patients, and then digestion by a restriction enzyme Stu-1, which recognizes a site that is absent in the mutant gene. In controls the 312 bp segment was digested into 235 and 77 bp fragments, while in patients there was no change in the size of the amplified 299 bp segment. The mutation was found in patients from 3 out of 5 unrelated Arab families. Both Iraqi-Jewish and Arab mutations were detectable in DNA extracted from blood and urine samples. The described simple methods of identifying the mutations should be useful for detection of the numerous potential carriers among the affected kindreds and for prenatal diagnosis using DNA extracted from chorionic villi samples.

New 2-Oxopyridine/2-Thiopyridine Derivatives Tethered to a Benzotriazole with Cytotoxicity on MCF7 Cell Lines and with Antiviral Activities

2020 ◽  
Vol 17 (2) ◽  
pp. 124-137 ◽  
Author(s):  
Adel Mahmoud Attia ◽  
Ahmed Ibrahin Khodair ◽  
Eman Abdelnasser Gendy ◽  
Mohammed Abu El-Magd ◽  
Yaseen Ali Mosa Mohamed Elshaier
Keyword(s):  
Dna Damage ◽  
Anticancer Agents ◽  
Active Compound ◽  
Docking Study ◽  
Base Pairs ◽  
Dna Base ◽  
Dna Base Pairs ◽  
Antiviral Activities ◽  
Active Methylene ◽  
Damage Study

Background:Perturbation of nucleic acids structures and confirmation by small molecules through intercalation binding is an intriguing application in anticancer therapy. The planar aromatic moiety of anticancer agents was inserted between DNA base pairs leading to change in the DNA structure and subsequent functional arrest.Objective:The final scaffold of the target compounds was annulated and linked to a benzotriazole ring. These new pharmacophoric features were examined as antiviral and anticancer agents against MCF7 and their effect on DNA damage was also assessed.Methods:A new series of fully substituted 2-oxopyridine/2-thioxopyridine derivatives tethered to a benzotriazole moiety (4a-h) was synthesized through Michael cyclization of synthesized α,β- unsaturated compounds (3a-e) with appropriate active methylene derivatives. The DNA damage study was assessed by comet assay. In silico DNA molecular docking was performed using Open Eye software to corroborate the experimental results and to understand molecule interaction at the atomic level.Results:The highest DNA damage was observed in Doxorubicin, followed by 4h, then, 4b, 4g, 4f, 4e, and 4d. The docking study showed that compound 4h formed Hydrogen Bonds (HBs) as a standard ligand with GSK-3. Compound 4h was the most active compound against rotavirus Wa, HAVHM175, and HSV strains with a reduction of 30%, 40%, and 70%, respectively.Conclusion:Compound 4h was the most active compound and could act as a prospective lead molecule for anticancer agent.

On the change of the order od stability of DNA base pairs as a result of the methylation of guanine

1988 ◽  
Vol 53 (9) ◽  
pp. 1943-1945
Author(s):  
Pavel Hobza ◽  
Camille Sandorfy
Keyword(s):  
Ab Initio ◽  
Base Pairs ◽  
Dispersion Energy ◽  
Dna Base ◽  
Dna Base Pairs

The interaction of the 6-O methylguanine cation with cytosine and thymine was studied using the ab initio SCF method in combination with a London type expression for dispersion energy. The structure of the complex formed with cytosine differs from that found previously with guanine itself.

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