Long repeating (TTAGGG) _n single-stranded DNA self-condenses into compact beaded filaments stabilized by G-quadruplex formation.

ABSTRACT: Conformations adopted by long stretches of single-stranded DNA (ssDNA) are of central interest in understanding the architecture of replication forks, R loops, and other structures generated during DNA metabolism in vivo This is particularly so if the ssDNA consists of short nucleotide repeats. Such studies have been hampered by the lack of defined substrates greater than ∼150 nt and the absence of high-resolution biophysical approaches. Here we describe the generation of very long ssDNA consisting of the mammalian telomeric repeat (5'-TTAGGG-3') _n , as well as the interrogation of its structure by EM and single-molecule magnetic tweezers (smMT). This repeat is of particular interest because it contains a run of three contiguous guanine residues capable of forming

SUBMITTER: Kar A 

PROVIDER: S-EPMC6005428 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature