Interactions of the human telomere sequence with the nanocavity of the α-hemolysin ion channel reveal structure-dependent electrical signatures for hybrid folds.

ABSTRACT: Human telomeric DNA consists of tandem repeats of the sequence 5'-TTAGGG-3', including a 3' terminal single-stranded overhang of 100-200 nucleotides that can fold into quadruplex structures in the presence of suitable metal ions. In the presence of an applied voltage, the α-hemolysin (α-HL) protein ion channel can produce unique current patterns that are found to be characteristic for various interactions between G-quadruplexes and the protein nanocavity. In this study, the human telomere in a complete sequence context, 5'-TAGGG(TTAGGG)3TT-3', was evaluated with respect to its multiple folding topologies. Notably, the coexistence of two interchangeable conformations of the K(+)-induced folds, hybrid-1 and hybrid-2, were readily resolved at a single-molecule level along with triplex folding

SUBMITTER: An N 

PROVIDER: S-EPMC3709467 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature