Thanks Paul for the quick reply! I wasn't aware of Coot's Transform Map by LSQ 
Fit function, I'll definitely try it out. Is there a command-line equivalent of 
this that I could use for batch processing multiple structures/maps that I want 
to align to a single reference? I'm using Pymol now because it was recommended 
to me, but clearly there are better solutions...


________________________________
From: Paul Emsley <[email protected]>
Sent: Friday, October 2, 2020 11:44 PM
To: Jade <[email protected]>; [email protected] <[email protected]>
Subject: Re: PyMol-exported CCP4 maps not being read correctly in Coot


On 02/10/2020 23:30, Jade wrote:
> I'm trying to use PyMol's matrix_copy command to align some PDB/CCP4 map 
> pairs, and I ran through the first example outlined here: 
> https://pymolwiki.org/index.php/Matrix_Copy, which fetches two PDBs/maps, 
> 1rx1 and 3dau, aligns the 1rx1 PDB to 3dau, and then matrix_copy's the 1rx1 
> map to the aligned 1rx1 PDB.
>
> The resulting maps look well-aligned in Pymol, but when I save these maps as 
> .ccp4 files and load them into Coot, Coot doesn't seem to register the 
> movement of the 1rx1 map. I chatted with Schrodinger about this and they 
> suspect that Coot is not reading the skew transformation flags SKWMAT and 
> SKWTRN that are written by Pymol, so the map stays in its original, unaligned 
> position. I was wondering if anyone has run into this same issue, and whether 
> there is an easy fix.


This is the reference that I'm using for CCP4/MRC maps:

https://www.ccpem.ac.uk/mrc_format/mrc2014.php

It doesn't mention skew.

After a bit of googling:

http://legacy.ccp4.ac.uk/html/maplib.html

This doesn't mention skew - but I've only just discovered it.

So yes, Coot does ignore the skew. It would be nice to have - I'll try
to get it done for 0.9.2.

So that answers your question.

But... I must ask... why are you even using PyMOL at all? Why not just
use the map transformation tool built into Coot?

Calculate -> Map Tools -> Transform Map by LSQ fit

Here, I did that example.

(It doesn't do SSM superposition via the gui - you'd have to cut and
paste the matrix)


Paul.



########################################################################

To unsubscribe from the COOT list, click the following link:
https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=COOT&A=1

This message was issued to members of www.jiscmail.ac.uk/COOT, a mailing list 
hosted by www.jiscmail.ac.uk, terms & conditions are available at 
https://www.jiscmail.ac.uk/policyandsecurity/

Reply via email to