DNA binding properties of the zinc‐bound and zinc‐free HIV nucleocapsid protein: supercoiled DNA unwinding and DNA‐protein cleavable complex formation

FEBS Letters

Seri, Iftach¹  Priel, Esther¹  Segal, Shraga¹  Henderson, Louis E²  Aflalo, Esther¹  Blair, Donald G³  Aboud, Mordechai¹  Arthur, Larry O² 

[1] Departement of Immunology and Microbiology, Cancer Research Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel;AIDS Vaccine Program, Program Resources Inc/Dyn Corp., NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201, USA;Microbiology Section, Laboratory of Molecular Oncology, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201, USA

关键词: HIV nucleocapsid protein;    Supercoiled DNA;    DNA-protein complex;   

DOI  :  10.1016/0014-5793(95)00208-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The HIV nucleocapsid (NC) protein contains, as those of other retroviruses, two Cys-His arrays which function as zinc finger binding domains. The nucleic acid binding properties of retroviral NC have been previously demonstrated. In this study, we characterized the DNA binding ability of the zinc-bound and zinc-free forms of HIV NC. We found that in addition to binding single-stranded DNA, both forms bind and unwind supercoiled plasmid DNA. The binding ability of the zinc-bound form was higher than the zinc-free form. In addition we showed the formation of NC protein-DNA cleavable complex which is the result of a presumably covalent bond formed between the protein and the phosphate moiety of the DNA backbone. The NC unwinding activity and the protein-DNA cleavable complex formation resembles the first step of the relaxing mechanism of DNA topoisomerase. Our results shed light on the possibility of a novel physiological function for the HIV NC protein in the viral life cycle.

【 授权许可】

Unknown