ABSTRACT
A series of forcible curved circular DNAs (cDNAs) were prepared to investigate the recognition features of human Topoisomerase I (hTopo I). The IC(50) can be modulated by the curvature degrees of cDNA. In addition, preferential bindings of hTopo I to cDNA with high curvature have been observed by AFM and EMSA.
Subject(s)
DNA Topoisomerases, Type I/metabolism , DNA, Circular/chemistry , DNA, Circular/metabolism , Electrophoretic Mobility Shift Assay , Humans , Microscopy, Atomic Force , Protein BindingABSTRACT
It is demonstrated that the right and left handedness of DNA supercoils can be engineered precisely and readily at the molecular level in vitro through utilization of the invading property of peptide nucleic acid.
Subject(s)
DNA, Circular/metabolism , Peptide Nucleic Acids/metabolism , DNA, Circular/chemistry , Genetic Engineering , Microscopy, Atomic Force , Peptide Nucleic Acids/chemistry , Plasmids/chemistry , Plasmids/metabolismABSTRACT
It is demonstrated that the shapes and magnitudes of DNA writhe can be precisely manipulated solely through maneuvering the nucleotide sequence of DNA and without the assistance of topoisomerases.
Subject(s)
DNA/chemistry , DNA/genetics , Nucleic Acid Conformation , Bacteriophage T4 , Base Sequence , DNA/chemical synthesis , Feasibility StudiesABSTRACT
Structural polymorphism is one of the important issues with regard to G-quadruplexes because the structural diversity may significantly affect their biological functions in vivo and their physical property in nano-material. A series of oligonucleotides with four repeat guanines sequence [d(G(4)T(n))(3)G(4) (n=1-6)] were designed. In this study, the effects of loop length on the formation of structures of G-quadruplex were investigated through the result of CD (circular dichroism) and 20% non-denatured polyacrylamide gel electrophoresis. Our studies demonstrate that the length of loop in 100mM KCl solution could predict the conformation of G-quadruplex.
