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MDFF data download


This page contains the input and output files of MDFF for each of the test targets.

Steps to run MDFF:

  1. 1. Generate the "*.psf", "*.dx", "*grid.pdb" and other files and assign the domain definition to the starting model using VMD based on the starting model and the cryo-EM density map (see MDFF tutorial )

  2. 2. Run the following command to perform the MDFF domain rigid-body assembly:
      mdff setup -o domain -psf xxx.psf
         -pdb xxx.pdb
         -griddx xxx.dx
         -gridpdb xxx-grid.pdb
         -extrab {xxx-extrabonds.txt xxx-extrabonds-cispt.txt xxx-extrabonds-chaira.txt}
         -gscale 1.0
         -minsteps 2000
         -numsteps 200000

  3. 3. After the rigid-body assembly, run the following command to perform the MDFF flexible refinement:
      mdff setup -o adk -psf xxx_autopsf.psf
         -pdb xxx_autopsf.pdb
         -griddx xxx_autopsf-grid.dx
         -gridpdb xxx_autopsf-grid.pdb
         -extrab {xxx-extrabonds.txt xxx-extrabonds-cispt.txt xxx-extrabonds-chaira.txt}
         -gscale 1.0
         -minsteps 2000
         -numsteps 500000

      mdff setup -o adk -psf xxx_autopsf.psf
         -pdb xxx_autopsf.pdb
         -griddx xxx_autopsf-grid.dx
         -gridpdb xxx_autopsf-grid.pdb
         -extrab {xxx-extrabonds.txt xxx-extrabonds-cispt.txt xxx-extrabonds-chaira.txt}
         -gscale 0.3
         -minsteps 2000
         -numsteps 500000
         -step 2

      mdff setup -o adk -psf xxx_autopsf.psf     ← last step for the final energy minimization
         -pdb xxx_autopsf.pdb
         -griddx xxx_autopsf-grid.dx
         -gridpdb xxx_autopsf-grid.pdb
         -extrab {xxx-extrabonds.txt xxx-extrabonds-cispt.txt xxx-extrabonds-chaira.txt}
         -gscale 10
          ← ξ in following tables is set for here
         -minsteps 2000
         -numsteps 0
         -step 3

    where "-numsteps" of the first two steps of the flexible fitting should set to 200000 in cMDFF (cases with map resolution < 5 Å).
Explanations:
  1. Initial model-----------------the starting model created through Situs by superposing each domain model into the density map.
  2. Domain definition-----------the predicted domain definition, which should be assigned into the initial model before running the domain rigid-body assembly. In the definition, domains are separated by semicolons, while segments of a discontinuous domain are separated by commas. For example, the domain definition of 4crnX (1-13,273-421;14-139;140-272;) means that the first domain is a discontinuous domain, where residue 1 to residue 13 belong to the first segment and residue 273 to residue 421 belong to the second segment. "14-139" indicates that the second domain is a continuous domain which covers residues from 14 to 139.
  3. MDFF final model-----------the final model refined by MDFF.
  4. Molprobity of final model--the Molprobity score of the MDFF final model calculated by "phenix.molprobity", which includes the following terms:
    1. Ramachandran outliers--------the percentage of residues with Ramachandran outlier.
    2. Ramachandran favored--------the percentage Ramachandran favored residues.
    3. Rotamer outliers---------------the percentage of residues with rotamer outliers.
    4. Clash score----------------------the number of serious steric overlaps (>0.4Å) per 1000 atoms.
    5. RMS(bonds)--------------------the root-mean-square deviations from standard bond lengths.
    6. RMS(angles)--------------------the root-mean-square deviations from standard bond angles.
    7. MolProbity score---------------the weighted sum of clashes, Ramachandran not-favored and rotamer outliers.
  5. MDFF log file----------------compressed file of MDFF logs which contains the following files:
    1. domain-step1_new.namd.log--the log file of the MDFF domain rigid-body assembly.
    2. adk-step1.namd.log------------the log file of the first step of the MDFF flexible refinement using the original density map.
    3. adk-step2.namd.log------------the log file of the second step of the MDFF flexible refinement using the original density map.
    4. adk-step3.namd.log------------the log file of the third step of the MDFF flexible refinement using the original density map.
      The following log files are included in the folder for cases with resolution <5Å because cMDFF is employed:
    1. adk-step1.namd.logN----------the log file of the first step of the MDFF flexible refinement using the N-th Gaussian blurred density map.
    2. adk-step2.namd.logN----------the log file of the second step of the MDFF flexible refinement using the N-th Gaussian blurred density map.
    3. adk-step3.namd.logN----------the log file of the third step of the MDFF flexible refinement using the N-th Gaussian blurred density map.
      Here, N=1,2,3,4,5, which corresponds to the half-width of 5, 4, 3, 2, 1, respectively.
  6. MDFF intermediate file----------all intermediate files generated by MDFF.
  7. ξ ------------ the weight (scaling factor, set by "-gscale" in MDFF) of the cryo-EM data restraint for the final energy minimization.
  8. MD_only---------- MDFF without the final energy minimization, which only performs the MD simulation.
NOTE:
  1. Please remember to run the domain rigid-body assembly and flexible refinement in order using the above commands. Otherwise, you may fail to run the MD simulation of MDFF due to the poor quality of initial models.
  2. The domain definition should be assigned to the starting model "initial_model.pdb" before running the domain rigid-body assembly of MDFF. The method to assign the domain can be found in the MDFF tutorial.
  3. Please read README.txt if you download the tarball file of each case.