Dear Garib,

Thank you very much. I will try the keyword.

> Your case: Do you see some sort of modulation of intensities in your images?
> Something like weak strong intensities along c axis? Or do you see elongated 
> peaks in the images.
Sorry I'm not sure what "modulation of intensities in image" is.
Do you mean something like described in this paper?
http://scripts.iucr.org/cgi-bin/paper?S0021889808010716
direct link to figure:
http://journals.iucr.org/j/issues/2008/03/00/he5398/he5398fig4.html

My diffraction images don't have such reflections.
But in some frames, severely elongated peaks along c* were observed.
Moreover, I found split peaks at high resolution (about 2.5A) area in
frames without elongated peaks.

I think my diffraction image is similar to what was discussed recently
in ccp4bb:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind1011&L=CCP4BB&F=&S=&P=312247
you can see the attached files of that archive.


Yours truly,

K. Yamashita

2010/12/9 Garib N Murshudov <[email protected]>:
> Dear Yamashita
>
> Refmac indeed does not apply vdw repulsions (antibumping restraints) if the 
> sum of occupancies is less than 1 and atoms do not belong to the same residue 
> with the same alt code. It means that if you have two or more molecules each 
> with occupancy less than 0.5 then there will be no intramolecular antibumping 
> restraints also. It is not what you would like. In these case you may want to 
> apply antibumping restraints within molecule. For this reason using keyword
>
> (if you have three copies and chain names are A B and C)
>
> vdwrepulsions exclude between chains A B C
>
> would be better. Then the program would apply antibumping restraints within 
> molecule but not between them.
>
> Your case: Do you see some sort of modulation of intensities in your images? 
> Something like weak strong intensities along c axis? Or do you see elongated 
> peaks in the images.
>
> regards
> Garib
>
>
>
>
> On 9 Dec 2010, at 01:11, Keitaro Yamashita wrote:
>
>> Dear Garib,
>>
>> Sorry I'm a little confused.
>>
>> As Eleanor said, Is it true that Refmac doesn't apply vdw restraints
>> if the sum of the atoms occupancies is <= 1?
>>
>>> If you want to deal with translational disorder (e.g. you have a modulated 
>>> crystal then there is another way.
>> In my data, there are crystallographic 4-fold axis on c-axis (P4 21 2)
>> and pseudo-translation vector (0.1, 0.1, 0.5), which is indicated by
>> native patterson peak with 22% height of the origin.
>>
>> I can see very clear density at certain position around the 4-fold axis.
>> And around the shifted position (+0.1, +0.1, +0.5), there's definitely
>> the same density but they are superposed with their symmetry mates --
>> I think  they are statically (packing) disordered.
>>
>> Is my case "translational disorder" as you said?
>> If so, how can I solve it?
>>
>>
>> Yours truly,
>>
>> K. Yamashita
>>
>> 2010/12/9 Garib N Murshudov <[email protected]>:
>>> In refmac you can remove vdw interactions between chains using the 
>>> following command
>>>
>>> It is an example:
>>>
>>> vdwr exclude between chains A B
>>>
>>> or between resdues:
>>>
>>> vdwr exclude between residues first residue 123 chain A second residue 155 
>>> chain B
>>>
>>>
>>> Regards
>>> Garib
>>>
>>>
>>> On 8 Dec 2010, at 16:09, Keitaro Yamashita wrote:
>>>
>>>> Dear all,
>>>>
>>>> I'm refining complex structure against X-ray diffraction data with
>>>> packing disorder.
>>>> (Some domains overlap with their symmetry mates (4-fold), so their
>>>> occupancies are set to 0.25)
>>>>
>>>> I'd like to know whether refinement programs can exclude any
>>>> interaction among symmetry mates from geometric term in target
>>>> function.
>>>> Can it be done only for specific chains?
>>>>
>>>> I was thankfully taught phenix.refine could do that with the option
>>>> pdb_interpretation.custom_nonbonded_symmetry_exclusion in phenixbb.
>>>>
>>>> I'd very much like to know whether Refmac5, CNS or other programs can do 
>>>> that.
>>>>
>>>> (When I tried to refine using Refmac5, the output told many vdw
>>>> repulsions with symmetry mates.)
>>>>
>>>>
>>>> Thank you very much in advance,
>>>>
>>>> K. Yamashita
>>>
>>>
>
>

Reply via email to