Structure of native four-repeat satellite III sequence with non-canonical base interactions.

ABSTRACT: Tandem-repetitive DNA (where two or more DNA bases are repeated numerous times) can adopt non-canonical secondary structures. Many of these structures are implicated in important biological processes. Human Satellite III (HSat3) is enriched for tandem repeats of the sequence ATGGA and is located in pericentromeric heterochromatin in many human chromosomes. Here, we investigate the secondary structure of the four-repeat HSat3 sequence 5'-ATGGA ATGGA ATGGA ATGGA-3' using X-ray crystallography, NMR, and biophysical methods. Circular dichroism spectroscopy, thermal stability, native PAGE, and analytical ultracentrifugation indicate that this sequence folds into a monomolecular hairpin with non-canonical base pairing and B-DNA characteristics at concentrations below 0.9 mM. NMR studies at 0.05-

SUBMITTER: Chen E 

PROVIDER: S-EPMC11014236 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature