Dear Kavya, I don't think it is likely you have five MSE and one MET. Rather, I would guess the side-chain has some disorder, i.e. one or more alternative conformations. If you don't see density for alternative conformations, the best way to model the disorder might be partial occupancy of the MSE that gives negative difference density peaks. Mark
Quoting Kayashree M: Dear users, I had posted this question already but in a different context. One of the Se-Met derivatised protein that we have solve is a homodimer (with 4 MET in the chains that crystallised) of which one chain has 3 MSE residues, while the other chain has only 2 MSE. Are there any such instances in PDB, where two homodimer (or any mer) wherein each has different percentage of MSE? Because when we change the only MET to MSE a negative density would arise. The tools to analyse anomalous peaks is not giving peaks for the MSE residues as the data was collected at 1.541Ang wavelength. Thank you Kavya -- This message has been scanned for viruses and dangerous content byMAILSCANNER[1], and is believed to be clean. Links: ------ [1] http://www.mailscanner.info/ Mark J van Raaij Laboratorio M-4 Dpto de Estructura de Macromoléculas Centro Nacional de Biotecnología - CSIC c/Darwin 3, Campus Cantoblanco 28049 Madrid tel. 91 585 4616 email: mjvanra...@cnb.csic.es
