Nucleic Acids Research, Vol 25, Issue 11 2221-2226, Copyright © 1997 by Oxford University Press
MJ Allen, EM Bradbury and R Balhorn
A novel method for reconstituting sperm chromatin was used to investigate
how protamine 1 condenses DNA. Complexes formed in vitro using linearized
plasmid DNA were imaged and measured by atomic force microscopy (AFM). The
structures formed were found to be highly dependent on the sample
preparation method used for reconstitution. Interstrand, side-by-side
fasiculation of DNA and toroidal-like structures only 1-2 DNA diameters
thick were observed for complexes formed in solution following direct
mixing of the DNA and protamine. Large chromatin aggregates were also
observed on the mica. However, if the DNA was first allowed to attach to
the mica prior to addition of the protamine, well-defined toroidal
complexes were formed without any observed DNA fasiculation or aggregate
formation. The diameter of the toroids measured 30.6-50.2 nm (mean 39.4
nm). The dimensions of these structures indicate that the condensed DNA is
stacked vertically by four to five turns, with each coil containing as
little as 360-370 bp of 'B'-form DNA. This approach for preparing and
imaging DNA-protamine complexes permits the analysis of intermediate
structures 'trapped' on the mica as partially formed toruses of
nucleoprotamine.
ARTICLES
AFM analysis of DNA-protamine complexes bound to mica
Digital Instruments, 520 East Montecito Street, Santa Barbara, CA 93103, USA. malleri@di.com
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  X.-M. Hou, X.-H. Zhang, K.-J. Wei, C. Ji, S.-X. Dou, W.-C. Wang, M. Li, and P.-Y. Wang Cisplatin induces loop structures and condensation of single DNA molecules Nucleic Acids Res., April 1, 2009; 37(5): 1400 - 1410. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Zhang, M. J. McCauley, L. J. Maher III, M. C. Williams, and N. E. Israeloff Mechanism of DNA flexibility enhancement by HMGB proteins Nucleic Acids Res., March 1, 2009; 37(4): 1107 - 1114. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Sarkar, I. Vitoc, I. Mukerji, and N. V. Hud Bacterial protein HU dictates the morphology of DNA condensates produced by crowding agents and polyamines Nucleic Acids Res., February 16, 2007; 35(3): 951 - 961. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Oliva Protamines and male infertility Hum. Reprod. Update, July 1, 2006; 12(4): 417 - 435. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Mudrak, N. Tomilin, and A. Zalensky Chromosome architecture in the decondensing human sperm nucleus J. Cell Sci., October 1, 2005; 118(19): 4541 - 4550. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. D. Vilfan, C. C. Conwell, and N. V. Hud Formation of Native-like Mammalian Sperm Cell Chromatin with Folded Bull Protamine J. Biol. Chem., May 7, 2004; 279(19): 20088 - 20095. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Muriel, E. Segrelles, V. Goyanes, J. Gosalvez, and J. L. Fernandez Structure of human sperm DNA and background damage, analysed by in situ enzymatic treatment and digital image analysis Mol. Hum. Reprod., March 1, 2004; 10(3): 203 - 209. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Brewer, M. Corzett, E. Y. Lau, and R. Balhorn Dynamics of Protamine 1 Binding to Single DNA Molecules J. Biol. Chem., October 24, 2003; 278(43): 42403 - 42408. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Brewer, M. Corzett, and R. Balhorn Condensation of DNA by Spermatid Basic Nuclear Proteins J. Biol. Chem., October 4, 2002; 277(41): 38895 - 38900. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. V. Klaus, J. R. McCarrey, A. Farkas, and W. S. Ward Changes in DNA Loop Domain Structure During Spermatogenesis and Embryogenesis in the Syrian Golden Hamster Biol Reprod, May 1, 2001; 64(5): 1297 - 1306. [Abstract] [Full Text]
|
|
|
|
 |
|
 Y. E. Yu, Y. Zhang, E. Unni, C. R. Shirley, J. M. Deng, L. D. Russell, M. M. Weil, R. R. Behringer, and M. L. Meistrich Abnormal spermatogenesis and reduced fertility in transition nuclear protein 1-deficient mice PNAS, April 25, 2000; 97(9): 4683 - 4688. [Abstract] [Full Text] [PDF]
|
|