Hi, I'm attempting to run ResolveCryoEM, and I have a few questions about setting the job up correctly. My half-maps were reconstructed with C4 symmetry to ~2 Å (CryoSPARC), and my model was refined into the density with the "Ncs constraints" box checked (Phenix RSR). My sample is a protein-DNA complex (4 copies of a protein protomer, 4 copies of a ssDNA protomer). I'm running Phenix 1.21.1-5286-000 (the latest installation provided by SBGrid). In the first version of the run, I only supplied the two half-map files and a seq file. Question 1: My current seq.dat file looks like this (as mentioned previously in the forum, I was getting errors when I tried the version where my seq.dat file has only 1 protomer and I set the number of copies to 4 in the GUI field "Copies of sequence file in map"):
protein_protomer1 MGSRSG... protein_protomer2 MGSRSG... protein_protomer3 MGSRSG... protein_protomer4 MGSRSG... DNA_protomer1 AAAAAA DNA_protomer2 AAAAAA DNA_protomer3 AAAAAA DNA_protomer4 AAAAAA
Currently, Phenix is reading in the "AAAAAA" as a protein chain ("Chain types considered: PROTEIN"). How do I tell Phenix that those are deoxyadenosines, not alanines? Question 2: Is Phenix automatically detecting the C4 symmetry and density-modifying with that constraint? The resulting map looks symmetric in the noise, but I don't see anything in the log suggesting that it knows the symmetry. Here are some settings from the log that seem relevant (all left to default values): refine_symmetry_in_denmod = True use_symmetry_in_denmod = False symmetry_in_denmod_last_cycle_only = True fraction_ncs = None I attempted to supply a symmetry file (the output of a MapSymmetry job on the full map = "symmetry_from_map.ncs_spec"), but the file fails to load into the input ("Phenix error: Phenix did not recognize the file type for ****/symmetry_from_map.ncs_spec"). Question 3: A part of my protein is disordered and does not appear in the cryo-EM density (and was thus left unmodeled). Is it correct to leave that piece out of the seq.dat file? Question 4: If I include a model in the input, Phenix demands a symmetry file, but I couldn't get my symmetry file to load as explained above. What is the symmetry file supposed to look like? Thank you! -Josh