And what if the site(s) is(are) a mixture of bound metal ions? What if Mg++, Ca++, Na+, Mn++, et al. are bound at the same site(s)? Can the diffraction data rule that out?
________________________________ From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Faisal Tarique [faisaltari...@gmail.com] Sent: Thursday, April 17, 2014 3:13 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] metal ion coordination Dear all Can anybody please explain what is the classical metal ion coordination for Mg2+, Ca+ and Na+ with Oxygen atom and the average distance with these metal ions..does the distance vary with the type of metal ion and its coordination with oxygen atom..what is the best way to identify the correct metal ion in the electron density in the vicinity of negatively charged molecule mostly oxygen containing molecule..In one of my paper the reviewer has asked me to check whether the octahedrally coordinated Mg+ is Ca+ ion..and similarly raised doubt about the identity of the Na+ ion as well..his argument was based on metal ion to oxygen distance..I am attaching the figure with this mail..i request you to please shed some light on this area and help me in clearing some doubts regarding this. -- Regards Faisal School of Life Sciences JNU
