Human chromosomal centromere (AATGG)n sequence forms stable structures with unusual base pairs.
Nine DNA sequences related to the purine strand of the human centromeric satellite (AATGG)n (CCATT)n repeat have been studied by two-dimensional nuclear magnetic resonance spectroscopy. Earlier studies have suggested that the structure of (AATGG)n sequence has an equilibrium between the duplex form and a fold-back form. Structural refinement of d(CAATGG) and its related sequences by an NOE-constrained simulated annealing procedure reveals that the duplex form incorporates dynamic type-I G-A base pairs. 1D exchangeable proton NMR data support this model. The reverse sequence motif (GGTAA) destabilizes the structure.
Biophysics Division, University of Illinois at Urbana-Champaign 61801.
T N
TN
Jaishree
A H
AH
Wang
D001482:Base Composition; D001483:Base Sequence; D002503:Centromere; D002877:Chromosomes, Human; D004276:DNA, Satellite / Q000737:chemistry*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012091:Repetitive Sequences, Nucleic Acid
D004276:DNA, Satellite