Nonalternating purine pyrimidine sequences can form stable left-handed DNA duplex by strong topological constraint.
Nucleic Acids Res
; 50(2): 684-696, 2022 01 25.
Article
em En
| MEDLINE
| ID: mdl-34967416
ABSTRACT
In vivo, left-handed DNA duplex (usually refers to Z-DNA) is mainly formed in the region of DNA with alternating purine pyrimidine (APP) sequence and plays significant biological roles. It is well known that d(CG)n sequence can form Z-DNA most easily under negative supercoil conditions, but its essence has not been well clarified. The study on sequence dependence of Z-DNA stability is very difficult without modification or inducers. Here, by the strong topological constraint caused by hybridization of two complementary short circular ssDNAs, left-handed duplex part was generated for various sequences, and their characteristics were investigated by using gel-shift after binding to specific proteins, CD and Tm analysis, and restriction enzyme cleavage. Under the strong topological constraint, non-APP sequences can also form left-handed DNA duplex as stable as that of APP sequences. As compared with non-APP sequences, the thermal stability difference for APP sequences between Z-form and B-form is smaller, which may be the reason that Z-DNA forms preferentially for APP ones. This result can help us to understand why nature selected APP sequences to regulate gene expression by transient Z-DNA formation, as well as why polymer with chirality can usually form both duplexes with left- or right-handed helix.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Purinas
/
Pirimidinas
/
DNA Forma Z
/
Conformação de Ácido Nucleico
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China