Re: [ccp4bb] MTZ cell troubles after sortmtz reindexing from P321 to C2

Protein crystallography Programs for crystallography X-ray detectors
Basic tutorials:
Protein Peptide

CCP4bb navigation

CCP4bb <-- 2008 <-- March 2008 <-- 07 March 2008

Previous message:
Subject: Re: MTZ cell troubles after sortmtz reindexing from P321 to C2
From: Phil Evans pre {- at -} MRC-LMB {- dot -} CAM {- dot -} AC {- dot -} UK
Date: 2008-03-07

Next message:
Subject: Re: Molecular replacement of a multidomain protein
From: Lucas Bleicher lbleicher {- at -} YAHOO {- dot -} COM
Date: 2008-03-07

Subject: Re: MTZ cell troubles after sortmtz reindexing from P321 to C2
From: "George M {- dot -} Sheldrick" gsheldr {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE
Date: 2008-03-07

Just for the record, if you feed the data into XPREP (using Tim Gruene's
mtz2sca if necessary) it will almost certainly give you the choice of
space groups - with an indication of which is the most likely - and do
the necessary cell and index transformations automatically. I recommend
inputting unmerged data in such cases!

George

Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-2582

On Fri, 7 Mar 2008, Pietro Roversi wrote:

> Dear all,
> after much sweat and grief I managed to index my data in
> P321 but looking at the symmetry I think they might be C2: reindexing
> from P321 to C2 with the 2h+k, k, l operator in sortmtz produces the
> right cell (and yes I did tick the "Reduce reflexions to the asymmetric
> unit" button so that noreduce is not among the sortmtz keywords):
>
> P321 209.3168 209.3168 40.6822 90.0000 90.0000 120.0000
> C2 362.5473 209.3168 40.6822 90.0000 90.0000 90.0000
>
> But: scala then decides that the asymmetric unit is not the right one
> and it mysteriously changes cell parameters (which I think points to a
> bug in the sortmtz process of reindexing):
>
> Reciprocal space symmetry:
> Space group: "C 1 2 1" Point group: "PG2" Laue group: "2/m"
> Reference asymmetric unit: "k>=0 and (l>0 or (l=0 and h>=0))"
> (change of basis may be applied)
>
> and I end up with this C2 cell in the mtz output from scala:
>
> 285.9320 285.9320 40.6824 90.0000 90.0000 90.0000
>
> I have tried OUTPUT ORIGINAL ans some such in scala but to no avail.
>
> Now please don't all tell me to go back and reindex-reintegrate these
> images - although I might have to do it to get the best out of these
> data once I am convinced they are monoclinic.
>
> Rather, I would appreciate suggestions on what program to feed the
> multirecord mtz to sort its asymmetric unit in C2 so that scala does not
> play tricks on me; or what keyword to feed scala to keep reflexions in
> the current asymmetric unit (and use cad or sftools afterwards on the
> scaled/merged file)
>
> Thanks
>
> Pietro
>
>
>
> --
> Pietro Roversi
> Sir William Dunn School of Pathology, Oxford University
> South Parks Road, Oxford OX1 3ER, England UK
> Tel. 0044-1865-275385
>

CCP4bb navigation

CCP4bb <-- 2008 <-- March 2008 <-- 07 March 2008

Previous message:
Subject: Re: MTZ cell troubles after sortmtz reindexing from P321 to C2
From: Phil Evans pre {- at -} MRC-LMB {- dot -} CAM {- dot -} AC {- dot -} UK
Date: 2008-03-07

Next message:
Subject: Re: Molecular replacement of a multidomain protein
From: Lucas Bleicher lbleicher {- at -} YAHOO {- dot -} COM
Date: 2008-03-07