Sticky DNA: Effect of the Polypurine·Polypyrimidine Sequence

摘要: The polypurine.polypyrimidine sequence requirements for the formation of sticky DNA were evaluated in Escherichia coli plasmid systems to determine potential occurrence this conformation throughout biological systems. A mirror repeat, dinucleotide tract (GA.TC)(37), which is ubiquitous eukaryotes, formed DNA, but shorter sequences 10 or 20 repeats inert. (GGA.TCC)(n) inserts (where n = 126, 159, and 222 bp) also DNA. As shown previously, control (GAA.TTC)(150) (450 readily adopted X-shaped structure; however, structure has never been found nonpathogenic (GAAGGA.TCCTTC)(65) same approximate length (390 bp). that replete with tracts can form triplexes slipped structures lacks long repeating motifs (the 2.5-kbp intron 21 from polycystic kidney disease gene 1) was Interestingly, (GAA.TTC)(n) 176 80) cloned into when pair direct, not indirect (inverted), orientation. stabilities triple base (Watson-Crick Hoogsteen) interactions DNA/DNA associated triplex region conformations account these observations. Our results have significant chemical implications function unusual Friedreich's ataxia.