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The helicase-like domains of type III restriction enzymes trigger long-range diffusion along DNA.

ABSTRACT: Helicases are ubiquitous adenosine triphosphatases (ATPases) with widespread roles in genome metabolism. Here, we report a previously undescribed functionality for ATPases with helicase-like domains; namely, that ATP hydrolysis can trigger ATP-independent long-range protein diffusion on DNA in one dimension (1D). Specifically, using single-molecule fluorescence microscopy we show that the Type III restriction enzyme EcoP15I uses its ATPase to switch into a distinct structural state that diffuses on DNA over long distances and long times. The switching occurs only upon binding to the target site and requires hydrolysis of ~30 ATPs. We define the mechanism for these enzymes and show how ATPase activity is involved in DNA target site verification and 1D signaling, roles that are common in DNA metabolism: for example, in nucleotide excision and mismatch repair.

SUBMITTER: Schwarz FW

PROVIDER: S-EPMC3646237 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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The helicase-like domains of type III restriction enzymes trigger long-range diffusion along DNA.

Schwarz Friedrich W FW Tóth Júlia J van Aelst Kara K Cui Guanshen G Clausing Sylvia S Szczelkun Mark D MD Seidel Ralf R

Science (New York, N.Y.) 20130401 6130

Helicases are ubiquitous adenosine triphosphatases (ATPases) with widespread roles in genome metabolism. Here, we report a previously undescribed functionality for ATPases with helicase-like domains; namely, that ATP hydrolysis can trigger ATP-independent long-range protein diffusion on DNA in one dimension (1D). Specifically, using single-molecule fluorescence microscopy we show that the Type III restriction enzyme EcoP15I uses its ATPase to switch into a distinct structural state that diffuses ...[more]

PMID: 23599494

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