NMR CHARACTERIZATION OF A TRIPLE-STRANDED COMPLEX FORMED BY HOMO-PURINE AND HOMO-PYRIMIDINE DNA STRANDS AT 1/1 MOLAR RATIO AND ACIDIC PH

被引：23

作者：

BHAUMIK, SR ^{[1
]}

CHARY, KVR ^{[1
]}

GOVIL, G ^{[1
]}

LIU, KL ^{[1
]}

MILES, HT ^{[1
]}

机构：

[1] NIDDKD,BETHESDA,MD 20892

来源：

NUCLEIC ACIDS RESEARCH | 1995年 / 23卷 / 20期

关键词：

D O I：

10.1093/nar/23.20.4116

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Homo-purine (d-TGAGGAAAGAAGGT) and homopyrimidine (d-CICCTTTCTTCC) oligomers have been designed such that they are complementary in parallel orientation. When mixed in a 1:1 molar ratio, the system adopts an antiparallel duplex at neutral pH with three mismatched base pairs, On lowering the pH below 5.5, a new complex is formed, The NMR results show the coexistence of a intermolecular pyrimidine.purine:pyrimidine DNA tripler and a single stranded oligopurine at this PH. The tripler is stabilized by five T.A:T, four C+.G:C and two mismatched triads, namely, C+.G-T and T.A-C. This tripler is further stabilized by a Hoogsteen C+.G base-pair on one end, Temperature dependence of the imino proton resonances reveals that the triplex dissociates directly into single strands around 55 degrees C, without duplex intermediates. parallel duplexes are not formed under any of the conditions employed in this study.

引用

页码：4116 / 4121

页数：6

共 32 条

[1] STRUCTURES FOR POLYNUCLEOTIDE COMPLEXES POLY(DA).POLY(DT) AND POLY(DT).POLY(DA).POLY(DT) [J].