Characterization of the MCM homohexamer from the thermoacidophilic euryarchaeon Picrophilus torridus
| Autor: | Swati Saha, Kasturi Goswami, Jasmine Arora |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Gene Expression
Thermoplasmales Article chemistry.chemical_compound Adenosine Triphosphate Minichromosome maintenance ATP hydrolysis Cloning Molecular Multidisciplinary Picrophilus torridus biology Minichromosome Maintenance Proteins Protein Stability Hydrolysis DNA Helicases Helicase DNA Hydrogen-Ion Concentration biology.organism_classification RNA Helicase A GINS DNA-Binding Proteins Enzyme Activation Biochemistry chemistry biology.protein Protein Multimerization Protein Binding |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | The typical archaeal MCM exhibits helicase activity independently invitro. This study characterizes MCM from the euryarchaeon Picrophilus torridus. While PtMCM hydrolyzes ATP in DNA-independent manner, it displays very poor ability to unwind DNA independently and then too only under acidic conditions. The protein exists stably in complex with PtGINS in whole cell lysates, interacting directly with PtGINS under neutral and acidic conditions. GINS strongly activates MCM helicase activity, but only at low pH. In consonance with this, PtGINS activates PtMCM-mediated ATP hydrolysis only at low pH, with the amount of ATP hydrolyzed during the helicase reaction increasing more than fifty-fold in the presence of GINS. While the stimulation of MCM-mediated helicase activity by GINS has been reported in MCMs from P.furiosus, T.kodakarensis and very recently, T.acidophilum, to the best of our knowledge, this is the first report of an MCM helicase demonstrating DNA unwinding activity only at such acidic pH, across all archaea and eukaryotes. PtGINS may induce/stabilize a conducive conformation of PtMCM under acidic conditions, favouring PtMCM-mediated DNA unwinding coupled to ATP hydrolysis. Our findings underscore the existence of divergent modes of replication regulation among archaea and the importance of investigating replication events in more archaeal organisms. |
| Databáze: | OpenAIRE |
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