Hello, it doesn't look like a phosphate very much, to be honest, and being so close to the carboxylate suggests it isn't. Is there any chance that it is an alternative conformation of the Arg side chain? If you model it as water, is there residual positive difference density?
Best wishes, Jon Cooper. [email protected] Sent from Proton Mail mobile -------- Original Message -------- On 17 Dec 2023, 10:46, Arpita Goswami wrote: > Dear All, > > Hope you all are doing well. > > The density in the image (in link below) is fitted with PO4 ion, although the > crystallization condition has both mono and dihydrogen phosphate which is not > fitting without hydrogen. But the resolution is 2.5 A, so hydrogen may not be > put in, or is there any way to do so? Otherwise placing water is the final > option. > > https://i.postimg.cc/4N7q2K0p/Screenshot-from-2023-12-17-16-07-07.png > > Also the density is quite close to Aspartate, so PO4 may not be right. Can it > be dihydrogen phosphate as two positively charged residues (Specially the > lysine) are also nearby to neutralize positive charge? Other ions in the > crystallization condition are Cl-, K+ and Na+. These are not put as both > aspartate and lysine are at comparable distances from the density. The pH is > 6.2 in which dihydrogen phosphate is reported to interact with aspartate > (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855859/). > > Waiting eagerly for your reply. > -- > > Thanks and Merry Christmas in advance. > Best Regards, > Arpita > > --------------------------------------------------------------- > > 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/
