The catalytic core of Leishmania donovani RECQ helicase unwinds a wide spectrum of DNA substrates and is stimulated by replication protein A
| Autor: | Agneyo Ganguly, Suparna Khatun, Debajyoti De, Gugulothu Sriram Bharath, Mayukh Chakraborty, Kumari Shikha, Susmita Ghosh, Swagata Mukhopadhyay, Amar Gupta |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
DNA Replication
RecQ helicase DNA Single-Stranded Biochemistry Catalysis Substrate Specificity chemistry.chemical_compound Catalytic Domain Replication Protein A parasitic diseases medicine Annealing activity Holliday junction Humans Bloom syndrome Molecular Biology Replication protein A DNA Cruciform biology RecQ Helicases Chemistry Walker motifs Helicase Cell Biology DNA medicine.disease enzymes and coenzymes (carbohydrates) biology.protein Leishmaniasis Visceral Leishmania donovani |
| Zdroj: | The FEBS journalReferences. 289(2) |
| ISSN: | 1742-4658 |
| Popis: | RecQ helicases are superfamily 2 (SF2) DNA helicases that unwind a wide spectrum of complex DNA structures in a 3' to 5' direction and are involved in maintaining genome stability. RecQ helicases from protozoan parasites have gained significant interest in recent times because of their involvement in cellular DNA repair pathways, making them important targets for drug development. In this study, we report biophysical and biochemical characterization of the catalytic core of a RecQ helicase from hemoflagellate protozoan parasite Leishmania donovani. Among the two putative RecQ helicases identified in L. donovani, we cloned, overexpressed and purified the catalytic core of LdRECQb. The catalytic core was found to be very efficient in unwinding a wide variety of DNA substrates like forked duplex, 3' tailed duplex and Holliday junction DNA. Interestingly, the helicase core also unwound blunt duplex with slightly less efficiency. The enzyme exhibited high level of DNA-stimulated ATPase activity with preferential stimulation by forked duplex, Holliday junction and 3' tailed duplex. Walker A motif lysine mutation severely affected the ATPase activity and significantly affected unwinding activity. Like many other RecQ helicases, L. donovani RECQb also possesses strand annealing activity. Unwinding of longer DNA substrates by LdRECQb catalytic core was found to be stimulated in the presence of replication protein A (LdRPA-1) from L. donovani. Detailed biochemical characterization and comparison of kinetic parameters indicate that L. donovani RECQb shares considerable functional similarity with human Bloom syndrome helicase. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text