Dear All, These days my research often involves structure determination of the Antigen:Fab complexes, wherein the antigen structure is already known. Given this: (1). I would like to run AutoBuild in such a way that the program does not to touch antigen model, but only Re-builds only the Fab molecule; and (2). in some cases, due to structural-symmetry within the variable and constant domains of heavy- and light- chains, AutoBuild is searching and applying NCS operator while it is not present, and would like to avoid the same. How could these be done either in GUI or in command-line?!! Many Thanks in advance, Best Wishes Partha PS: Of course, when the data is at "high-enough resolution", I build Fab model manually after MR and Refinement. But, in the above case, resolution is only 3-ish angstrom.