I would proceed in I422 and refine to get a decent model anyway. I presume you have one molecule in that asymmetric unit? You don't give the pointless stats on the merging of symmetry equivalents. That would help decide whether the I point group is the more likely. The pseudo translation peak in P4 is 78% of the origin, which is high and makes it likely that the I4 point group with c-P4 reduced to C/3 is correct eleanor
On 7 May 2012 16:07, Zhou, Tongqing (NIH/VRC) [E] <tz...@mail.nih.gov>wrote: > Dear All,**** > > ** ** > > I have collected several dataset for an antibody:antigen complex. It > apparently indexed to P4 space group with large cell dimensions of > 191.7000/191.7000/311.0540. When I processed as P1 and ran Pointless, it > suggested P422 as space group. P4212 gives the best MR solution with 6 > mol/ASU (18 chains total ). However, ridigbody and subsequent refinement > with TLS could not reduce the r and r-free which stayed at ~48%. Tried to > go P4, P222…(12 mol/ASU) with twinning, but the refinement failed due to > insufficient computer memory (12 GB), it was also impossible to refine in > P1 due to the same reason.**** > > ** ** > > But for some data sets, HKL2000 also gave I4 space group with c axis > reduced to 1/3 of that of P4. With the I4 data (~2.7 A resolution), I422 > was the best MR space group (1 mol/ASU), the refinement went down to r=29% > and r-free=34%, but won’t go down further.**** > > ** ** > > Please advise if it’s possible to use the data **** > > ** ** > > ** ** > > *Tongqing* > > * * > > *Tongqing Zhou, Ph.D.* > > Staff Scientist**** > > Structural Biology Section**** > > Vaccine Research Center, NIAID/NIH**** > > Building 40, Room 4609B**** > > 40 Convent Drive, MSC3027**** > > Bethesda, MD 20892**** > > (301) 594-8710 (Tel)**** > > (301) 793-0794 (Cell)**** > > (301) 480-2658 (Fax)**** > > > ****************************************************************************** > **** > > The information in this e-mail and any of its attachments is confidential > and may contain sensitive information. It should not be used by anyone who > is not the original intended recipient. If you have received this e-mail in > error please inform the sender and delete it from your mailbox or any other > storage devices. National Institute of Allergy and Infectious Diseases > shall not accept liability for any statements made that are sender's own > and not expressly made on behalf of the NIAID by one of its representatives. > **** > > ********************************************************************** > > ** ** >
