Dear Jacob, The latest WHAT IF/WHAT_CHECK (http://swift.cmbi.ru.nl/servers/html/index.html --> Build/check/repai model --> template structure check) does ion checks in a way similar to WASP. It does take symmetry into account and also checks if your ions could be another ion. If you add a 'REMARK 280' to your PDB file it makes checks a bit more reliable. At any rate you should check the suggestions carefully by hand. At high resolution one tends to get alternate waters which really messes up things. Cheers, Robbie Joosten
---------------------------------------- > Date: Mon, 15 Feb 2010 14:26:25 -0600 > From: j-kell...@md.northwestern.edu > Subject: [ccp4bb] Distinguishing Between Na+ and H2O > To: CCP4BB@JISCMAIL.AC.UK > > Dear Crystallographers, > > I am looking at a 1.0 Angstrom structure which contains many waters, but I > am wondering whether some of them might really be sodium ions. Is there any > straightforward way to distinguish between these two, and if so, what is the > software which implements this? Although the electron density difference > between sodium and water should be very small, perhaps the binding geometry > would provide a clearer distinction? Has anybody encountered this question > before? > > Regards, > > Jacob Keller > > ******************************************* > Jacob Pearson Keller > Northwestern University > Medical Scientist Training Program > Dallos Laboratory > F. Searle 1-240 > 2240 Campus Drive > Evanston IL 60208 > lab: 847.491.2438 > cel: 773.608.9185 > email: j-kell...@northwestern.edu > ******************************************* > _________________________________________________________________ New Windows 7: Find the right PC for you. Learn more. http://windows.microsoft.com/shop
