Science · 2013 · 84 citations · 43 references
Life SciencesGeneticsMolecular BiologyEnzyme MechanismEnzymologyMicrobial GeneticsAtp HydrolysisEnzyme FunctionEnzyme StructureEnzyme-substrate RecognitionHelicase FunctionProximity EffectsDna Double HelixDouble-stranded Dna StructureGenetic Information CommunicationHelicase Conformational DynamicsHelicase-dna Substrate SpecificityRestriction EndonucleasesRestriction Enzyme DigestionType Iii Restriction Enzymes
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.
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NIH Image to ImageJ: 25 years of image analysis
Caroline A Schneider, Wayne Rasband, Kevin W. Eliceiri · Nature Methods · 2012 · 65.2K citations