title: DNA polymerase as a molecular motor and pump.
abstract: DNA polymerase is responsible for synthesizing DNA, a key component in the running of biological machinery. Using fluorescence correlation spectroscopy, we demonstrate that the diffusive movement of a molecular complex of DNA template and DNA polymerase enhances during nucleotide incorporation into the growing DNA template. The diffusion coefficient of the complex also shows a strong dependence on its inorganic cofactor, Mg2+ ions. When exposed to gradients of either nucleotide or cofactor concentrations, an ensemble of DNA polymerase complex molecules shows collective movement toward regions of higher concentrations. By immobilizing the molecular complex on a patterned gold surface, we demonstrate the fabrication of DNA polymerase-powered fluid pumps. These miniature pumps are capable of transporting fluid and tracer particles in a directional manner with the pumping speed increasing in the presence of the cofactor. The role of DNA polymerase as a micropump opens up avenues for designing miniature fluid pumps using enzymes as engines.
authors.affiliation: Department of Chemistry and ‡Department of Bioengineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States .
authors.forename: Samudra
authors.initials: S
authors.lastname: Sengupta
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Spiering
authors.forename: Krishna K
authors.initials: KK
authors.lastname: Dey
authors.forename: Wentao
authors.initials: W
authors.lastname: Duan
authors.forename: Debabrata
authors.initials: D
authors.lastname: Patra
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Butler
authors.forename: R Dean
authors.initials: RD
authors.lastname: Astumian
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Benkovic
authors.forename: Ayusman
authors.initials: A
authors.lastname: Sen
mesh_terms: D017122:Bacteriophage T4 / Q000201:enzymology; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D003838:Deoxyadenine Nucleotides / Q000378:metabolism; D004058:Diffusion; D008274:Magnesium / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009068:Movement
chemical_list: D003838:Deoxyadenine Nucleotides; D020409:Molecular Motor Proteins; D004259:DNA-Directed DNA Polymerase; D008274:Magnesium; C026600:2'-deoxyadenosine triphosphate