Structural insights into the N-terminal APHB domain of HrpA: mediating canonical and i-motif recognition.
Nucleic Acids Res
; 52(6): 3406-3418, 2024 Apr 12.
Article
em En
| MEDLINE
| ID: mdl-38412313
ABSTRACT
RNA helicases function as versatile enzymes primarily responsible for remodeling RNA secondary structures and organizing ribonucleoprotein complexes. In our study, we conducted a systematic analysis of the helicase-related activities of Escherichia coli HrpA and presented the structures of both its apo form and its complex bound with both conventional and non-canonical DNAs. Our findings reveal that HrpA exhibits NTP hydrolysis activity and binds to ssDNA and ssRNA in distinct sequence-dependent manners. While the helicase core plays an essential role in unwinding RNA/RNA and RNA/DNA duplexes, the N-terminal extension in HrpA, consisting of three helices referred to as the APHB domain, is crucial for ssDNA binding and RNA/DNA duplex unwinding. Importantly, the APHB domain is implicated in binding to non-canonical DNA structures such as G-quadruplex and i-motif, and this report presents the first solved i-motif-helicase complex. This research not only provides comprehensive insights into the multifaceted roles of HrpA as an RNA helicase but also establishes a foundation for further investigations into the recognition and functional implications of i-motif DNA structures in various biological processes.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
DNA Helicases
/
Proteínas de Escherichia coli
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China