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 <[email protected]> on behalf of Robert S Phillips <[email protected]> Sent: 18 June 2020 14:00 To: [email protected] <[email protected]> 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: [email protected] 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 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/
