Another cause of difficulty - nothing really to do with the spacegroup
selection - is when one copy of the model has much higher B factors than
others. Most MR searches assume that the copies contribute more or less
equally to scattering.
If you assign too high a symmetry this will make MR le
The space group in which you do the RF makes no difference (assuming
the model in each case is identical of course) because you're
superposing the same amount of scattering matter: it has nothing to do
with the fraction of the contents of the AU. In the high symmetry
space group with say 1 instanc
In my experience, the success of molecular replacement depends primarily
on the quality of the model. Thus if your model is good, even P1 will
work. Two extreme cases that I encountered were searching with a
monomer for what turned out to be 4 tetramers (thus first search only
accounted for 1/16
I think the question was not concerning right vs wrong space
group, but right vs a lower symmetry superset space group -
P4322 vs P43 for example. I would also be interested in
the answer.
At first glance it appears harder in the lower symmetry
because with each monomer you would be searching for
Ting-Wei Jiang wrote:
Dear experts,
Sorry for a simple question but confusing me so much!
Does it make bad effects on determining the number of identical
molecules in ASU by choosing low symmetry space group.
For example,If I choose lowest symmetry(p4) instead of higher
one(p43212).
Does it
Well P4 isnt a subgroup of P43212 - you would need P43
MR programs will often let you test several spacegroups. See Phaser MR
or MOLREP - I would try that and choose the best
Eleanor
On 02/16/2011 02:48 PM, Ting-Wei Jiang wrote:
Dear experts,
Sorry for a simple question but confusing me
Dear experts,
Sorry for a simple question but confusing me so much!
Does it make bad effects on determining the number of identical molecules in
ASU by choosing low symmetry space group.
For example,If I choose lowest symmetry(p4) instead of higher one(p43212).
Does it cause any trouble in dete
