Hi Chandra, That is an intriguing question. The problem is that even if you would data mine this, the data in the PDB would be incredibly skewed to whatever we managed to crystalise. And then there is the problem of poorly modeled metal sites. So the true answer will be elusive. Purely anecdotal, I tend to see more monodentate metal binding in protein structures. Apart from confirmation bias, it might be caused by bidentate coordination almost always having suboptimal geometry in terms of orbital overlap. Another issue is that monodentate binding is more evolutionary robust. In many metal sites you don’t need direct charge compensation by a formal charge. Polarisation is quite enough. That means that your coordinating oxygen can be replaced by quite a few residues. This is not the case in a bidentate setup.
HTH, Robbie From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Chandra Prakash Tiwari Sent: Monday, July 15, 2019 12:44 To: [email protected] Subject: [ccp4bb] Bidentate GLU vs two monodentate GLU in metalloproteins Dear all, What is more preferable or conserved by evolution point of view between glutamate acting as bidentate ligand by its carboxylate group or two monodentate GLU at metal binding site in natural metalloprotein. I was thinking 2 GLU are better than one bidentate GLU because if one GLU gets mutated other GLU will still be able to form a coordination bond to a metal. Please comment and help if i am right or wrong. ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
