Hello,

I can see additional density just next to Cys residues in my protein structure and it looks like BME is covalently linked to cys. I could form a disulfide bond between BME and Cys in "Refmac 5 review restrain" but when i subject it for refinement BME is thrown away (no disulfide bond). I also given Cif file in refinement but it didnot help. I have a feel that i am missing something in cif file. Can anyone suggest step  by step starting from adding BME to making a link with BME (Cys-BME) and then refinement?

 

Raj