[ccp4bb]

2009-08-10 Thread Guenter Fritz
Hi Sajid, the NADP /NAD binding sites are often composed of two sites: one site that is specific for the adenine/adenosine moiety and another site for the nicotinamide moiety. It can happen that you see the adenine in the density but not the nictoninamid tangling around. HTH Guenter I

[ccp4bb] PhD fellowship in structure determination of cys-loop receptors at University of Copenhagen

2009-08-10 Thread Michael Gajhede
General announcement and how to apply : http://www.farma.ku.dk/index.php?id=6811 Project description: http://www.farma.ku.dk/index.php/Project-10/6840/0/ Deadline for applications: Tuesday 25 August 2009 at 12 o'clock noon. About the group: http://www.farma.ku.dk/BR/ Please contact me if you

Re: [ccp4bb] pseudo-translational symmetry

2009-08-10 Thread Eleanor Dodson
First - there doesnt seem much to worry about. The Rs will be higher than usual when you have a strong pseudo-translation vector. There are many weak observations for the h k l=2n+1 reflections. But in cases like this is is very helpful to force the same indexing on all your different data

Re: [ccp4bb] pseudo-translational symmetry

2009-08-10 Thread alebus
Just a small comment on Eleanor's instructive advices : ... If your original structure has cell (a2= 47.3, b2=58.9, c2=67.6) and angles (alpha2=90, beta2=99.2, gamma2=90) and the second cell is (a1=67.5, b1=58.8, c1=98.9) and angles (alpha1=90, beta1=101.5, gamma1=90) ... I would force

Re: [ccp4bb] pseudo-translational symmetry

2009-08-10 Thread Eleanor Dodson
Oops - sorry to mislead you. Yes - you are absolutely right.. Eleanor ale...@pasteur.fr wrote: Just a small comment on Eleanor's instructive advices : ... If your original structure has cell (a2= 47.3, b2=58.9, c2=67.6) and angles (alpha2=90, beta2=99.2, gamma2=90) and the second cell

[ccp4bb] alternative graphics programs for OS X--summary

2009-08-10 Thread Patrick Loll
Hi, Thanks to the many replies to my queries about cheap/easy alternatives to Photoshop and CorelDraw on OS X. In a rare display of unanimity, the bulletin board spoke with essentially one voice: ALTERNATIVE TO PHOTOSHOP: Gimp (not gimpshop) http://www.gimp.org/ As one sage

Re: [ccp4bb] Electron Density Maps

2009-08-10 Thread Folmer Fredslund
Dear Pascal, 2009/8/10 Pascal Egea pas...@msg.ucsf.edu: Dear All, I am currently carrying the refinement of a structure and comparing the results obtained in Refmac, Phenix and CNS. While Phenix and Refmac write maps and their corresponding coefficients in mtz format allowing display of

Re: [ccp4bb] Electron Density Maps

2009-08-10 Thread Kevin Cowtan
If you want to display CNS maps in Coot and have them on the right scale, then you need to do one of two things. Either: 1. Don't use the map file, use the reflection file containing the map coefficients, or 2. Change the setting in CNS which controls the extent of the output map. Instead

[ccp4bb] calculation of radii

2009-08-10 Thread ashok kumar
Dear all i want to know how can i calculate the alpha helical radii of 3-D structure of a protein. Is there any programme to calculate the radii of alpha helix.

Re: [ccp4bb] How to model apo protein structure from solved ligand bound high resolution structure?

2009-08-10 Thread Satheesh Kumar Palani Nathan
Hi Donghui, It’s going to be tricky. Perhaps, you can predict some local rotamer variations around the ligand interacting regions. Predicting the global changes is difficult, particularly if you are anticipating a big conformational change. For example, in one of our structure, the active

[ccp4bb] Heavy atom searching with disulfides

2009-08-10 Thread Francis E Reyes
Hi all Has there been any work/reports of using disulfide restraints (number of heavy atoms as well as distance) for heavy atom searching/scoring for anomalous sulfur phasing? What resolution range would this be most effective? Thanks FR -

Re: [ccp4bb] Heavy atom searching with disulfides

2009-08-10 Thread George M. Sheldrick
The paper Acta Cryst. D59 (2003) 2125-2132 discusses searching for disulfides. In general this works for data truncated for phasing to between 2.1 and 2.9 A. If the resoltuions is higher than 2.1, you can search for individual sulfurs, if it is worse than 2.9 even fitting them as disulfides is

[ccp4bb] Pictures of DDM crystals?

2009-08-10 Thread Joe
Hi all, I am doing initial crystallization screening for a membrane protein purified in DDM. The actual concentration of DDM in the protein solution is 2 CMC after the protein concentration step (Amicon MWCO 50 kD used). I just found over 50 conditions out of 1000 give me crystals. Having

[ccp4bb] Disulfide bond survival in the presence of DTT?

2009-08-10 Thread Brad Bennett
Hi all- Got a perplexing thiol chemistry/phasing issue. To prevent non-native disulfide bonds from forming between free Cys but to preserve native disulfides, I have heard of using a very low (say 0.5 mM) concentration of DTT. I've recently come across a paper where the assignment of 3 disulfides

[ccp4bb] DNA binding protein

2009-08-10 Thread Neeraj
Hi all, I had a simple question about DNA binding protein. Is there an easy way to detect if your heterologously expressed protein is bound to DNA post purification. Also is there an easy way to strip the protein of DNA without any damage done to the protein in doing so. I would

[ccp4bb] hardware stereo in Coot on Mac

2009-08-10 Thread David Bruce McKay
Two questions RE hardware (dual images on CRT monitor, 3-D with stereo glasses) stereo on a Macintosh. 1 We have a configuration: Mac dual Intel processors OS 10.4.11 NVIDIA Quadro FX 4500 graphics card X11 version 1.1.3 It runs hardware stereo in O and Pymol , which don't require an X-

Re: [ccp4bb] DNA binding protein

2009-08-10 Thread Pascal Egea
Hi Neeraj, An absorption spectra between 220 and 400 nm (for example) should show you if there is DNA coming along with your protein. In theory A280 is about 1.7 times A260 for a pure protein sample. This is a rough estimate. If your peak is shifted towards 260 instead of 280 then you can suspect

Re: [ccp4bb] Pictures of DDM crystals?

2009-08-10 Thread Joe
I forgot the mention this: does anyone happen to have some pictures of DDM crystals? It would be very very helpful for me to take a look and get a sense how they look like. I appreciate your inputs and help. Thanks, Joe On Mon, Aug 10, 2009 at 4:47 PM, Joe gch...@gmail.com wrote: Hi all,

Re: [ccp4bb] DNA binding protein

2009-08-10 Thread Dima Klenchin
I had a simple question about DNA binding protein. Is there an easy way to detect if your heterologously expressed protein is bound to DNA post purification. Yes. UV absorbance. DNA absorbs UV strongly, proteins do not. DNA absorbs 260 more thn 280, the opposite is true for proteins.

Re: [ccp4bb] DNA binding protein

2009-08-10 Thread Chun Luo
TurboNuclease digests DNA and RNA to 1-4 base long fragments. It's very useful to remove nucleic acids during protein purification and virus purification. Another benefit of using TurboNuclease at cell lysis is to significantly reduce lysate viscosity. So it reduces the lysate volume for column

Re: [ccp4bb] DNA binding protein

2009-08-10 Thread Miles Pufall
I'd agree with Pascal as well, and can add that if you have a protein for which you use an affinity tag, often high salt (500mM) will strip the DNA off your protein, and might even keep it stable. Cheers - Miles On Aug 10, 2009, at 3:59 PM, Pascal Egea wrote: Hi Neeraj, An absorption

[ccp4bb] DS Visualizer ActiveX Control in PowerPoint

2009-08-10 Thread Yong-Fu Li
Hi, This is non-CCP4 related question, I apologize to those who are not interested. But I hope there might be someone over there with a good answer. Program: Accelry DS Visualizer 2.0 (Free ware). It has some interesting features. My intention: Create an image from pdb files and save as .msv

Re: [ccp4bb] DS Visualizer ActiveX Control in PowerPoint

2009-08-10 Thread Warren DeLano
Yong-Fu, Microsoft in its infinite wisdom decided to bury ActiveX functionality in Office 2007. To access Controls, you need to click on the big round button in the upper-left, select PowerPoint Options, choose then Popular tab and then check the Show Developer tab in the Ribbon option. The

Re: [ccp4bb] Disulfide bond survival in the presence of DTT?

2009-08-10 Thread Artem Evdokimov
Hi, I am sorry that I cannot recall the highest concentration of DTT that I ever used (inadvertently) when working with disulphide-containing proteins. However I have the following mildly useful suggestion: If you have properly formed -S-S- as well as a bunch of free -SH perhaps a safer

[ccp4bb] {Spam?} quick purification?

2009-08-10 Thread Mark Collins
Hi All A little off topic, but I am thinking about expressing and purifying 40+ mutants, for an assay, at maybe 1mg total protein each. I'd like the purification to be quick and easy (ie. one step) but cleaner than just a 6his-tag purification. Currently, my options are either GST, a

Re: [ccp4bb] {Spam?} quick purification?

2009-08-10 Thread Artem Evdokimov
Hi, Since you're considering a serious undertaking, it would be good to know whether your protein is decently expressed and reasonably characterized in its native state - before advising you on the process :) If your protein is normally expressed well, is soluble, and not aggregated - there's