Dear sir Thank you for clearing that. I checked back to see that HLC/D are invariably 0 for all reflections, with the non-zero HLA/B supposedly having been originated from the probability distribution of phases *calculated* by phaser. Hopefully, I have not misunderstood it.
Thanks and regards Nitin Kulhar On Thu, Feb 8, 2024 at 9:07 PM Randy John Read <rj...@cam.ac.uk> wrote: > Hi, > > Hendrickson-Lattman coefficients are just a way of storing phase > probability information, and they can come from different sources including > atomic models. Phaser puts in HL coefficients because they could be handy > under some circumstances for combining the phase information from > experimental phasing. You might notice that only A and B are non-zero for > the molecular replacement HL coefficients. That’s because the phase > probability distribution is unimodal for calculated phases, whereas it’s > generally bimodal for experimental phases (thus requiring more > coefficients). > > Best wishes, > > Randy Read > > > On 8 Feb 2024, at 14:32, Nitin Kulhar < > 00009dfccc771c91-dmarc-requ...@jiscmail.ac.uk> wrote: > > > > Dear all > > > > Is anomalous diffraction necessary for determining experimental phases > and the Hendrickson-Lattman coefficients (HLA, HLB, HLC, and HLD)? > > > > MR solution from Phaser 2.8.3 (interfaced in ccp4 8.0.000 suite) seems > to be generating HLA/B/C/D coefficients from an x-ray diffraction dataset. > > > > Wavelength: > > 1.54179 Angstrom. > > > > Sample: > > • > > Protein-small molecule ligand complex crystal. > > • No anomalous scatterer in the protein, the ligand, or the > crystallization condition. > > > > Data reduction: > > Xtriage and aimless analyses did not indicate significant anomalous > signal. > > > > I would appreciate any help in understanding the reasons for these > observations. > > > > Thanks and regards > > Nitin Kulhar > > PhD student > > c/o Dr Rajakumara Eerappa > > Macromolecular Structural Biology Lab > > Department of Biotechnology > > Indian Institute of Technology Hyderabad > > Kandi, Sangareddy > > Telangana, India - 502284 > > > > Disclaimer:- This footer text is to convey that this email is sent by > one of the users of IITH. So, do not mark it as SPAM. > > To unsubscribe from the CCP4BB list, click the following link: > > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > ----- > Randy J. Read > Department of Haematology, University of Cambridge > Cambridge Institute for Medical Research Tel: +44 1223 336500 > The Keith Peters Building > Hills Road E-mail: > rj...@cam.ac.uk > Cambridge CB2 0XY, U.K. > www-structmed.cimr.cam.ac.uk > > -- Disclaimer:- This footer text is to convey that this email is sent by one of the users of IITH. So, do not mark it as SPAM. ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
