Or try the other orthorhombic SGs..? Some general ideas for any such problem...
Is there evidence for a dimer in the asymmetric unit, or could your dimer be generated by the crystal 2-folds? Checks on data - all easily accessed from CCP4I2 .. First is the data OK - Wilson plot? twinning? r factors v batch etc.. Second - likely contents of asymmetric unit? Third , if there is likelty to be more than one molecule per asymm unit a)Is there non-crystallographic translation b) is the self rotation any help? But here your solution is the identity - ie the model fits your data without either rotation or translation! SOLU 6DIM ENSE ense_1 EULER 360.0 0.0 0.0 FRAC -0.00 -0.00 -0.00 BFAC -0.12 MULT 2 #TFZ==20. Could the model structure be isomorphous with your new one? Eleanor On Thu, 18 Jun 2020 at 14:06, David Briggs <david.bri...@crick.ac.uk> wrote: > Hi Robert, > > Have you tried lower symmetry spacegroups? Maybe your crystal is > 'almost-but-not-quite' orthorhombic and is in fact monoclinic, pretending > to be orthorhombic. > > Zanuda can do this for you. > > https://www.ccp4.ac.uk/newsletters/newsletter48/articles/Zanuda/zanuda.html > > Good luck, > > Dave > > -- > > Dr David C. Briggs > > Senior Laboratory Research Scientist > > Signalling and Structural Biology Lab > > The Francis Crick Institute > > London, UK > > == > > Diamond User Committee MX representative > > == > > about.me/david_briggs > ------------------------------ > *From:* CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Robert S > Phillips <p...@uga.edu> > *Sent:* 18 June 2020 14:00 > *To:* CCP4BB@JISCMAIL.AC.UK <CCP4BB@JISCMAIL.AC.UK> > *Subject:* [ccp4bb] Molecular replacement problem > > I've been pulling out my hair with this for a few months now. I have data > sets to 2.6 A for a new enzyme in the aminotransferase superfamily. > Unfortunately, the closest structure is only 25% identity. MR with PHASER > using the monomer was a complete failure. Since the minimum structure of > enzymes in the family is a dimer (the active site is formed at the > monomer-monomer interface), I used dimers for MR with PHASER. Most of the > results were marginal, but one looks good. However, it will not refine. > Everything I have done with this solution has failed, simulated annealing, > morphing, etc., it will not refine; AUTOBUILD and BUCCANEER with it do not > give any useable models, since they have poor statistics and low > completeness. The output from PHASER is below. > > ** SINGLE solution > > ** Solution written to PDB file: DGL_phaser.1.pdb > ** Solution written to MTZ file: DGL_phaser.1.mtz > Solution annotation (history): > SOLU SET RFZ=18.9 TFZ=23.0 PAK=0 LLG=193 TFZ==8.3 LLG=994 TFZ==20.1 > PAK=0 LLG=994 TFZ==20.1 > SOLU SPAC P 2 2 21 > SOLU 6DIM ENSE ense_1 EULER 360.0 0.0 0.0 FRAC -0.00 -0.00 -0.00 > BFAC -0.12 MULT 2 #TFZ==20.1 > SOLU ENSEMBLE ense_1 VRMS DELTA -3.5403 #RMSD 2.08 #VRMS 0.89 > > With LLG = 994 and TFZ = 20.1, isn't this a real solution? > > Robert S. Phillips > Professor of Chemistry and of Biochemistry and Molecular Biology > University of Georgia > Athens, GA 30602 > Phone: (706) 542-1996 > Fax: (706) 542-9454 > E-mail: rsphill...@chem.uga.edu > Web: http://tryptophan.net > <https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpod51004.outlook.com%2Fowa%2Fredir.aspx%3FC%3Dccbf42ffea5f48b1bf8e9bb950454bab%26URL%3Dhttp%253a%252f%252ftryptophan.net&data=02%7C01%7C%7Cd804f2e8aae94225588808d81387ab6d%7C4eed7807ebad415aa7a99170947f4eae%7C0%7C1%7C637280820702952452&sdata=DR11jkYMX2Y0wTZjbuY362yf%2FGNaIN5htG6HQaJ0XcE%3D&reserved=0> > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > <https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.jiscmail.ac.uk%2Fcgi-bin%2FWA-JISC.exe%3FSUBED1%3DCCP4BB%26A%3D1&data=02%7C01%7C%7Cd804f2e8aae94225588808d81387ab6d%7C4eed7807ebad415aa7a99170947f4eae%7C0%7C1%7C637280820702962441&sdata=l9jsMT6ToXm9Revf3u89X0dkHoHBFP6xpnWkBgLjm7k%3D&reserved=0> > > The Francis Crick Institute Limited is a registered charity in England and > Wales no. 1140062 and a company registered in England and Wales no. > 06885462, with its registered office at 1 Midland Road London NW1 1AT > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > ######################################################################## 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/
