Hi Asmahan, The pLDDT scores for an AlphaFold prediction are in the bfactor column of the PDB atomic model file. Here is an example of lines from such a file where the value 85.53 is the pLDDT for residue 1. ATOM 1 N ASP B 1 -0.818 -36.026 -12.912 1.00 85.53 N ATOM 2 CA ASP B 1 0.545 -35.783 -13.373 1.00 85.53 C ATOM 3 C ASP B 1 0.706 -34.352 -13.882 1.00 85.53 C The bfactor is assigned to every atom. But pLDDT is only assigned for each residue and measures CA position so you might want to look at only the CA lines. $ grep CA ~/Downloads/ChimeraX/AlphaFold/prediction_14/af252_unrelaxed_rank_1_model_2.pdb ATOM 2 CA ASP B 1 0.545 -35.783 -13.373 1.00 85.53 C ATOM 10 CA CYS B 2 1.983 -32.130 -13.721 1.00 95.45 C ATOM 16 CA PRO B 3 3.029 -30.770 -17.151 1.00 93.20 C ATOM 23 CA SER B 4 6.629 -31.094 -18.066 1.00 93.36 C You can also write the values into a ChimeraX attribute file using ChimeraX commands select #1@CA save ~/Desktop/plddt.defattr attrName bfactor models #1 selectedOnly true and that file looks like the following attribute: bfactor recipient: atoms match mode: 1-to-1 /A:1@CA 56.150001525878906 /A:2@CA 53.33000183105469 /A:3@CA 53.59000015258789 /A:4@CA 59.380001068115234 documentation here https://www.cgl.ucsf.edu/chimerax/docs/user/commands/save.html#attributes Tom

On Nov 22, 2022, at 7:08 AM, Asmahan Alghamdi <Asmahan.Alghamdi@nottingham.ac.uk> wrote:

Dear Tom, I hope you are well. I was wondering if there is away to export pLDDT scores of the best predicted model of a protein using ChimeraX e.g. 1.5 (which I am using in my investigations)?

Thank you very much. Asmahan