Hi Elaine,

I compared the SASA values generated by chimera and chimeraX for a few PDB files and I noticed that whenever the SASA value of a residue is reported to be zero by chimera, the same residue's SASA value is reported to be -1.42 by chimeraX. Few examples are 18.A and 38.A of the PDB ID 1A62.

Method used to calculate SASA of residues in chimera: Tools > Structure analysis > Render by attribute

Method used to calculate SASA of residues in chimeraX: I ran the following commands: measure sasa protein;info residues attribute area

Why is this happening? Kindly help.

Prathvi Singh,

Research Fellow,

Department of Biological Sciences & Bioengineering,

Indian Institute of Technology, Kanpur-208016