I thought some of the script writers out there might want to know that in the latest daily builds residues have a "uniprotIndex" attribute which gives the position of the residues relative to their UniProt sequence, if the correspondence can be determined. To determine the correspondence the structure must have valid PDB HEADER and SEQRES records, and the PDB web site must be reachable (to use their UniProt mapping service). --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu