Hi, Is there any way to turn off automatic secondary structure assignment upon opening a pdb file that does not contain secondary assignments? Cheers, Sumitro ------------------------------------------------------------------------ --------------------------------------------------------------------- ... Opening B-7301_SRWGYQVKH_1K5N.pdb... Computing secondary structure assignments... Computed secondary structure assignments (see reply log) Model 2 (B-7301_SRWGYQVKH_1K5N.pdb) appears to be a protein without secondary structure assignments. Automatically computing assignments using 'ksdssp' and parameter values: energy cutoff -0.5 minimum helix length 3 minimum strand length 3 Use command 'help ksdssp' for more information. ... ------------------------------------------------------------------------ ---------------------------------------------------------------------