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	<id>https://wiki.uni-konstanz.de/ccp4/api.php?action=feedcontributions&amp;feedformat=atom&amp;user=Cwilliam</id>
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	<updated>2026-04-17T11:43:43Z</updated>
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	<entry>
		<id>https://wiki.uni-konstanz.de/ccp4/index.php?title=Crystal_growth:_Protein-DNA_complexes&amp;diff=1489</id>
		<title>Crystal growth: Protein-DNA complexes</title>
		<link rel="alternate" type="text/html" href="https://wiki.uni-konstanz.de/ccp4/index.php?title=Crystal_growth:_Protein-DNA_complexes&amp;diff=1489"/>
		<updated>2009-07-20T11:51:43Z</updated>

		<summary type="html">&lt;p&gt;Cwilliam: New page: Tips suggested by the CCP4 community as the best way to crystallize a protein/DNA complex   1.	One of the biggest variables is to screen different lengths of DNA  2.	Good to try both blunt...&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Tips suggested by the CCP4 community as the best way to crystallize a protein/DNA complex &lt;br /&gt;
&lt;br /&gt;
1.	One of the biggest variables is to screen different lengths of DNA&lt;br /&gt;
&lt;br /&gt;
2.	Good to try both blunt and sticky ends.  Perhaps as a first attempt try sticky ends with complementary ends&lt;br /&gt;
&lt;br /&gt;
3.	Could try purification by gel filtration if the complex is tight. Probably easier, quicker, cheaper and just as successful just to mix and pray!&lt;br /&gt;
&lt;br /&gt;
4.	 Screen for crystals using a wide variety of crystal screens&lt;br /&gt;
Natrix, Nucleix, PEGS, Index, JCSG core, MPD screen, PEG ion screen, home made PEG salt screen (+/- Mg++)&lt;br /&gt;
&lt;br /&gt;
5.	DNA can be ordered from a wide range of suppliers.  Could try using un-purified DNA for screening, purify your own or order HPLC purified DNA&lt;br /&gt;
&lt;br /&gt;
6.	Good to try a wide range of ratio’s for protein/DNA.  Most popular seems to be a ratio of 1/1.2&lt;br /&gt;
&lt;br /&gt;
7.	Other useful tips?&lt;br /&gt;
&lt;br /&gt;
Protein DNA crystals can be very fragile so good idea to screen with cryoprotectant in the screen to save manipulations&lt;br /&gt;
Test crystals with a gel to see if DNA is present&lt;br /&gt;
Use of SAXS to get molecular envelop of complex&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Several references below:&lt;br /&gt;
&lt;br /&gt;
Schultz, S. C., Shields, G. C. &amp;amp; Steitz, T. A. (1990).&lt;br /&gt;
Crystallization of Escherichia coli catabolite gene activator protein with its DNA binding site. J. Mol.Biol. 213, 159–166.&lt;br /&gt;
&lt;br /&gt;
Tan et al, Crystallization of the Yeast MATa2/MCM1/DNA Ternary Complex: General Methods and Principles for Protein/DNA Cocrystallization J. Mol. Biol. (2000) 297, 947-959&lt;br /&gt;
&lt;br /&gt;
Cannone et al, Crystallization of bFGF-DNA aptamer complexes using a&lt;br /&gt;
Sparse Matrix designed for protein–nucleic acid complexes Journal of Crystal Growth, 2001 232 (2001) 409–417&lt;br /&gt;
&lt;br /&gt;
Book chapter 8 from Crystallization of nucleic acids and proteins: a practical approach.&lt;br /&gt;
Edited by A.Ducruix and R. Giege (Oxford University Press)&lt;/div&gt;</summary>
		<author><name>Cwilliam</name></author>
	</entry>
	<entry>
		<id>https://wiki.uni-konstanz.de/ccp4/index.php?title=Crystals&amp;diff=1488</id>
		<title>Crystals</title>
		<link rel="alternate" type="text/html" href="https://wiki.uni-konstanz.de/ccp4/index.php?title=Crystals&amp;diff=1488"/>
		<updated>2009-07-20T11:31:49Z</updated>

		<summary type="html">&lt;p&gt;Cwilliam: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;== Crystal Characterization ==&lt;br /&gt;
* [[Birefringence]]&lt;br /&gt;
&lt;br /&gt;
== Crystal Imperfections ==&lt;br /&gt;
* [[Diffuse Scattering]]&lt;br /&gt;
* [[Incommensurate Lattices]]&lt;br /&gt;
&lt;br /&gt;
== Crystal Growth ==&lt;br /&gt;
&lt;br /&gt;
* [[Modifying the protein to crystallize better]]&lt;br /&gt;
* [[Crystallization screens and methods]]&lt;br /&gt;
* [[I have crystals, but are they salt?]]&lt;br /&gt;
* [[Conditions prone to salt crystallization]]&lt;br /&gt;
* [[Biophysical methods]] for evaluation of crystallization tendency&lt;br /&gt;
* [[Improving crystal quality]]&lt;br /&gt;
* [[Robots for crystallization setup]]&lt;br /&gt;
* [[Visualization of crystal growth]]&lt;br /&gt;
* [[Crystal mounting]]&lt;br /&gt;
* [[Robots for crystal mounting]]&lt;br /&gt;
* [[Robots for crystallization monitoring]]&lt;br /&gt;
* [[Crystal growth: Tips and Tricks]]&lt;br /&gt;
* [[Crystal growth: Protein-DNA complexes]]&lt;br /&gt;
* [[BMCD|Biomolecular crystallization database]]&lt;br /&gt;
&lt;br /&gt;
== Crystal handling ==&lt;br /&gt;
* [[Sticky crystals]]&lt;br /&gt;
* [[Soaking with heavy atoms]]&lt;br /&gt;
&lt;br /&gt;
== Data collection ==&lt;br /&gt;
* [[X-ray generators and detectors]] (experiences) &lt;br /&gt;
* [[Synchrotrons]]&lt;br /&gt;
* [[Cryo]]&lt;br /&gt;
* [[Strategies]]&lt;br /&gt;
* [[Data quality]]&lt;br /&gt;
* [[Radiation damage]]&lt;br /&gt;
* [[Data collection: Tips and Tricks]]&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
&lt;br /&gt;
* crystallization of soluble proteins (see also [[Improving crystal quality]])&lt;br /&gt;
&lt;br /&gt;
* crystallization of membrane proteins (see also [[Improving crystal quality#Improving diffraction quality of membrane protein crystals]])&lt;br /&gt;
# Wiener MC (2004) A pedestrian guide to membrane protein crystallization. Methods 34(3), 364-372.&lt;br /&gt;
# Loll PJ (2003) Membrane protein structural biology: the high throughput challenge. J. Struct. Biol. 142(1), 144-153.&lt;br /&gt;
# Methods and Results in Crystallization of Membrane Proteins Iwata S (Ed.), San Diego, CA: International University Line. (2003)&lt;br /&gt;
# Macromolecular Crystallography Protocols, Volume 1: Preparation and Crystallization of Macromolecules. Doublie S (Ed.), Totowa, NJ: Humana Press. (2007)&lt;br /&gt;
# Structural Biology of Membrane Proteins. Grisshammer R, &amp;amp; Buchanan SK (Eds.), Cambridge, UK: Royal Society of Chemistry. (2006)&lt;/div&gt;</summary>
		<author><name>Cwilliam</name></author>
	</entry>
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