This is really a Q to Kevin Cowtan..
Is it important to have a "proper" mask for DMMULTI? I had always
thought it was self correcting and as long as it was
big enough then the program would update it?
Eleanor
Peter Adrian Meyer wrote:
I would be very much afraid that the only way to get the masks
properly would be to edit them interactively.
I used to do that in the PHASES package by Bill Furey and MapViewX
which is still alive and kicking under the BnP flagship.
I am pretty sure though that Dr. DVD will be online soon and will
point out the correct succession of MAMA/RAVE/O commands ;-)
As far as I know, mapview does section by section 2d editing. Unless
mapview_x has been updated recently, O is probably less painful for
interactively editing masks (although my prefered set of mask editing
commands in O have been declared obsolete).
Pete
A.
On Feb 22, 2007, at 1:08, Jianghai Zhu wrote:
Forgot to mention that the NCSs are improper.
On Feb 21, 2007, at 6:22 PM, Jianghai Zhu wrote:
Dear all,
I have two low resolution (3.8 A) MAD data sets from two different
space groups. There are 4 copies of my molecule in one space
group and 2 copies in the other. The density-modified maps from
these data sets are poor, but still allow me to build a crude
model on them. All the domains should be at the right or close to
right orientations and positions. I would like to try multi-
crystal averaging to improve my maps. Since I already have the
model, I used NCSMASK to make 6 masks for the 6 copies of my
model. Then I used DMMULTI to perform the multi-crystal
averaging. The maps came out of DMMULTI showed great
improvement. Some densities were not seen before showed up
nicely. However, after I read the manual carefully, I realize
that DMMULTI would not take care of the mask overlap. So some
regions in my density map between the NCS-related and symmetry-
related molecules must be messed up. Could any expert out there
give me some suggestions about how to make proper NCS masks for
DMMULTI? Thanks at advance.
Jianghai
Pete Meyer
Fu Lab
BMCB grad student
Cornell University
