THYMINE METHYL-GROUPS STABILIZE THE PUTATIVE A-FORM OF THE SYNTHETIC DNA POLY(AMINO(2)DA-DT)

被引：16

作者：

KYPR, J ^{[1
]}

SAGI, J ^{[1
]}

SZAKONYI, E ^{[1
]}

EBINGER, K ^{[1
]}

PENAZOVA, H ^{[1
]}

CHLADKOVA, J ^{[1
]}

VORLICKOVA, M ^{[1
]}

机构：

[1] HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY

来源：

BIOCHEMISTRY | 1994年 / 33卷 / 13期

关键词：

D O I：

10.1021/bi00179a003

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：

Poly(amino2dA-dT) easily isomerizes into a non-B conformer which most authors think is an A-form. We synthesized new DNA analogs poly(amino2dA-ethyl5dU) and poly(amino2dA-dU) to show that they do not prefer this conformer. Hence the putative A-form is, like Z-DNA of poly(dG-dC) but unlike A-DNA, strongly stabilized by the methyl group in position 5 of the pyrimidine base. In addition, the putative A-form is induced by divalent cations while it does not need any alcohol to be stable, both properties being typical for Z-DNA again but quite unusual with A-DNA. Despite these similarities, the putative A-form is also distinct from Z-DNA, as poly(amino2dA-dT) is shown to isomerize into a Z-form in the NaCl + NiCl2 solvent system like poly(dA-dT). The present data indicate that the putative A-form of poly(amino2dA-dT) differs in a significant way from all canonical conformers of DNA. Furthermore, the studies of the poly(amino2dA-dT) family of polydeoxynucleotides reveal a novel type of conformational switch in DNA. We also report the B-Z transitions of poly(amino2dA-ethyl5dU) and poly(amino2dA-dU) and their transitions into the putative A-form in aqueous alcohol solutions.

引用

页码：3801 / 3806

页数：6

共 51 条

[1] RIGHT-HANDED AND LEFT-HANDED HELIXES OF POLY[D(A-T)].POLY[D(A-T)] INVESTIGATED BY INFRARED-SPECTROSCOPY [J].