Hi Hailiang,

I tried the following code for PDB 1SX3:

*******************
phenix.tls 1SX3.pdb combine_tls=true
********************

but it ended up with:

***********
======================= TLS groups from PDB file header
=======================

Sorry: Bad TLS selection: start index > end index.
*******************

yes, the PDB file

http://www.pdb.org/pdb/files/1SX3.pdb

has the wrong TLS selection:

(...)

REMARK   3   TLS GROUP : 10                                                     
REMARK   3    NUMBER OF COMPONENTS GROUP : 4                                    
REMARK   3    COMPONENTS        C SSSEQI   TO  C SSSEQI                         
REMARK   3    RESIDUE RANGE :   D   561        D   135

(...)

I couldn't find any documentation on this matter, but based on my survey of PDB entries I found that the start_index (561 above) should be less than end_index (135 above), which is not the case for this TLS group.

By the way, do I have to specify the selection or phenix.tls will
automatically do it based on PDB header?

The TLS information is extracted from PDB file header automatically.

Pavel.