Hi Rohit, you might be interested in the following paper:
Buried chloride stereochemistry in the Protein Data Bank BMC Structural Biology 2014, 14:19 doi:10.1186/s12900-014-0019-8 http://www.biomedcentral.com/1472-6807/14/19 Best, Oliviero On Tue, January 20, 2015 10:53, Eleanor Dodson wrote: > Also it just might be useful to do an anomalous Fourier - Cl has a weak > signal, but may be visible if the phases are good. cf any peaks to ones > over the S atoms to get a measure of what you might expect- Eleanor > > > > On 20 January 2015 at 07:17, Robbie Joosten <r.joos...@nki.nl> wrote: > >> Hi Rohit, >> >> The pictures you sent are not that informative. There are a few things >> you >> can use to distinguish chloride from water. Chloride prefers nitrogens >> over >> oxygens as ligands. Also the coordination lengths are higher than those >> of >> water, typically between 3 and 3.5Å. Usually, the coordination is not as >> pretty as that of cations. >> >> HTH, >> Robbie >> ------------------------------ >> Van: rohit kumar <rohit...@gmail.com> >> Verzonden: 20-1-2015 08:05 >> Aan: CCP4BB@JISCMAIL.AC.UK >> Onderwerp: [ccp4bb] chloride or water >> >> >> Dear all, >> >> I am solving a data of 3.0 Å resolution. In the active site we found an >> unidentified blob. The crystallization condition is (PEG 3350-25%, >> Naformate-200mM, MES (100mM)-6.5pH, and Nacl-200mM). >> Can anyone suggest what it could be? If I suppose that, it is chloride, >> how could someone differentiate between a chloride moiety and water. >> below I am showing the coot figure in two different orientations. >> >> Thanks in advance... >> >> >> [image: Inline image 1] >> >> >> >> [image: Inline image 2] >> >> >> >> >> >> -- >> WITH REGARDS >> Rohit Kumar Singh >> Lab. no. 430, >> P.I. Dr. S. Gourinath, >> School of Life Sciences, >> Jawaharlal Nehru University >> New Delhi -110067 >> >
