Di Fabrizio, Enzo M.
KAUST DepartmentSMILEs Lab
Physical Sciences and Engineering (PSE) Division
Biological and Environmental Sciences and Engineering (BESE) Division
Imaging and Characterization Core Lab
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AbstractThe structure of DNA was determined in 1953 by x-ray fiber diffraction. Several attempts have been made to obtain a direct image of DNA with alternative techniques. The direct image is intended to allow a quantitative evaluation of all relevant characteristic lengths present in a molecule. A direct image of DNA, which is different from diffraction in the reciprocal space, is difficult to obtain for two main reasons: the intrinsic very low contrast of the elements that form the molecule and the difficulty of preparing the sample while preserving its pristine shape and size. We show that through a preparation procedure compatible with the DNA physiological conditions, a direct image of a single suspended DNA molecule can be obtained. In the image, all relevant lengths of A-form DNA are measurable. A high-resolution transmission electron microscope that operates at 80 keV with an ultimate resolution of 1.5 Å was used for this experiment. Direct imaging of a single molecule can be used as a method to address biological problems that require knowledge at the single-molecule level, given that the average information obtained by x-ray diffraction of crystals or fibers is not sufficient for detailed structure determination, or when crystals cannot be obtained from biological molecules or are not sufficient in understanding multiple protein configurations.
CitationThe structure of DNA by direct imaging 2015, 1 (7):e1500734 Science Advances
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- Authors: Walczak M, Grubmüller H
- Issue date: 2014 Aug
- IPET and FETR: experimental approach for studying molecular structure dynamics by cryo-electron tomography of a single-molecule structure.
- Authors: Zhang L, Ren G
- Issue date: 2012
- Structure of wet specimens in electron microscopy. Improved environmental chambers make it possible to examine wet specimens easily.
- Authors: Parsons DF
- Issue date: 1974 Nov 1
- Cryo-negative staining.
- Authors: Adrian M, Dubochet J, Fuller SD, Harris JR
- Issue date: 1998 Apr-Jun
- Direct imaging of DNA fibers: the visage of double helix.
- Authors: Gentile F, Moretti M, Limongi T, Falqui A, Bertoni G, Scarpellini A, Santoriello S, Maragliano L, Proietti Zaccaria R, di Fabrizio E
- Issue date: 2012 Dec 12