Zbyszek Otwinowski and Fred Vellieux suggested to run the self-rotation
on Fcalcs. This suggestion "solved" the problem, since there are similar
peaks on the kappa=180° planes as well. However, I wasn't able to get
rid of those peaks by playing around with resolution and integration
radius. I must say that I am surprized, because - as Eleanor pointed out
- I also expected to find peaks on the kappa=180° planes only in case of
P6522 symmetry. Anyway, this experience reminds me to run some simple
tests beforehand.
-Peer
On 29.04.2015 15:31, Eleanor Dodson wrote:
Well - PG P6/mmm (possible SG P6522) will have peaks at kappa = 180
omega = 90 phi = 0 30 60 etc..
But if there is only one molecule / asymm unit there cant be an extra
2-fold.
How big are the relative domains? Your interesting domain couldnt just
be cleaved off could it?
Eleanor
On 29 April 2015 at 12:59, Peer Mittl <mi...@bioc.uzh.ch
<mailto:mi...@bioc.uzh.ch>> wrote:
We are working with a multi-domain protein crystallized in SG P6_5
with one molecule per asymmetric unit. The structure was refined
at 2.00 A resolution with reasonable R-factors but unfortunately
the domain we are most interested in seems to be disordered.
Interestingly, the self-rotation function shows peaks on the
kappa=180° plane (omega=90°, phi=19° (and every 30°)), with more
than 50% origin peak height. Therefore, we are wondering if
perhaps the space group assignment might be sub-optimal. Any
explanations how these self-rotation peaks could occur and how we
could extract meaningful information to resolve the disordered
domain are welcome.
Best regards,
Peer
P.S. Some additional information: pointless suggests SG P6_5, the
data doesn't seem to be twinned (L-test), the refined part of the
structure has no "internal symmetry" and refinement in P1 doesn't
reveal the "lost" domain.
