Chicken erythrocyte nucleosomes have a defined orientation along the linker DNA--a scanning force microscopy study.

The orientation of nucleosomes was investigated using scanning force microscopy (SFM) of hypotonically spread chicken chromatin. A virtual cross section parallel to the substrate at half maximum height of the nucleosomal structure revealed an elliptical shape. The orientation of the major axis of this ellipse was investigated in reference to the direction of the axis of the nucleosomal chain. An alignment of the nucleosomes along the nucleosomal chain was observed, with more than 50% of the nucleosomes aligned with the long axis of the chain within < or = 30 degrees deviation. The alignment distribution peaked at 10-20 degrees. The application of SFM-based image processing for the structural investigation of a protein-DNA complex demonstrates the potential for this approach in structural molecular biology.

[1]  Y. Lyubchenko,et al.  Atomic force microscopy of nucleoprotein complexes. , 1995, Scanning microscopy.

[2]  George Chumanov,et al.  Colloidal metal films as a substrate for surface-enhanced spectroscopy , 1995 .

[3]  Z. Shao,et al.  Biological atomic force microscopy: what is achieved and what is needed , 1996 .

[4]  Donald E. Olins,et al.  Spheroid Chromatin Units (ν Bodies) , 1974, Science.

[5]  D. Bazett-Jones,et al.  Conformational characterization of nucleosomes by principal component analysis of their electron micrographs , 1993, Journal of microscopy.

[6]  H. Zentgraf,et al.  Reversible in vitro packing of nucleosomal filaments into globular supranucleosomal units in chromatin of whole chick erythrocyte nuclei. , 1980, European journal of cell biology.

[7]  David Keller,et al.  Biochemical and structural applications of scanning force microscopy , 1994 .

[8]  J. Dubochet,et al.  DNA at the entry-exit of the nucleosome observed by cryoelectron microscopy. , 1995, Journal of structural biology.

[9]  J. Gatewood,et al.  Atomic force microscope measurements of nucleosome cores assembled along defined DNA sequences. , 1993, Biochemistry.

[10]  J. Vesenka,et al.  Scanning force microscopy of chromatin. , 1995, Scanning microscopy.

[11]  W Fritzsche,et al.  Scanning force microscopy reveals ellipsoid shape of chicken erythrocyte nucleosomes. , 1996, Biophysical journal.

[12]  K. Sokolov,et al.  Unusual extinction spectra of nanometer-sized silver particles arranged in two-dimensional arrays , 1996 .

[13]  A. Klug,et al.  Structure of the nucleosome core particle at 7 Å resolution , 1984, Nature.

[14]  J. Baldwin.  Protein-nucleic acid interactions in nucleosomes , 1992 .

[15]  K. Adolph,et al.  Surface structure of isolated metaphase chromosomes. , 1983, Experimental cell research.

[16]  D. Bazett-Jones,et al.  Histone hyperacetylation can induce unfolding of the nucleosome core particle. , 1990, Nucleic acids research.

[17]  H. Hansma,et al.  Biomolecular imaging with the atomic force microscope. , 1994, Annual review of biophysics and biomolecular structure.

[18]  T. Jovin,et al.  Scanning force microscopy of chromatin fibers in air and in liquid. , 2006, Scanning.