Thermoplasma acidophilum Cdc6 protein stimulates MCM helicase activity by regulating its ATPase activity.

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TitleThermoplasma acidophilum Cdc6 protein stimulates MCM helicase activity by regulating its ATPase activity.
Publication TypeJournal Article
Year of Publication2008
AuthorsHaugland, GTeien, Sakakibara, N, Pey, AL, Rollor, CR, Birkeland, N-K, Kelman, Z
JournalNucleic Acids Res
Volume36
Issue17
Pagination5602-9
Date Published2008 Oct
ISSN1362-4962
KeywordsAdenosine Triphosphatases, Archaeal Proteins, DNA Helicases, DNA Replication, DNA-Binding Proteins, Thermoplasma
Abstract

The minichromosome maintenance (MCM) proteins are thought to function as the replicative helicases in archaea. In most archaeal species studied, the interaction between MCM and the initiator protein, Cdc6, inhibits helicase activity. To date, the only exception is the helicase and Cdc6 proteins from the archaeon Thermoplasma acidophilum. It was previously shown that when the Cdc6 protein interacts with MCM it substantially stimulates helicase activity. It is shown here that the mechanism by which the Cdc6 protein stimulates helicase activity is by stimulating the ATPase activity of MCM. Also, through the use of site-specific substitutions, and truncated and chimeric proteins, it was shown that an intact Cdc6 protein is required for this stimulation. ATP binding and hydrolysis by the Cdc6 protein is not needed for the stimulation. The data suggest that binding of Cdc6 protein to MCM protein changes the structure of the helicase, enhancing the catalytic hydrolysis of ATP and helicase activity.

DOI10.1093/nar/gkn548
Alternate JournalNucleic Acids Res.
PubMed ID18757887
PubMed Central IDPMC2553600