Hi, I have successed done this under Modeller 4. But under Modeller 6v2, the old script doesn't work. My top file is as follow:

READ_MODEL FILE = 'xenl.pdb' RENAME_SEGMENTS SEGMENT_IDS = 'X', RENUMBER_RESIDUES = off WRITE_MODEL FILE = 'xenl.mol', HETATM_IO = on The log file reported that assgn___547E> Incorrect element type for variable: RENUMBER_RESIDUES Element, element type: OFF 4 Command line: RENAME_SEGMENTS SEGMENT_IDS = 'X', RENUMBER_RESIDUES = OFF assgn___525E> Error in TOP variable assignment. compile_563E> Please correct the errors reported above and rerun MODELLER. recover____E> ERROR_STATUS >= STOP_ON_ERROR: 1 1

I have checked the libary file top.ini in modeller4 and modeller6v2 about RENUMBER_RESIDUES. Under modeller4 , 64 LOGICAL RENUMBER_RESIDUES 1 on # whether to renumber residues from 1 to N Under modeller6v2, 41 INTEGER RENUMBER_RESIDUES 0 # starting residue index for renumbering residues

Is it possible to change a pdb file's chain id without renumbering the residues ? Thank you very much! With best regards, Lesheng