Frequently Asked Questions¶
I installed the software, how do I test if it is correctly installed?¶
Because different users have different settings and requirements for their clusters or workstations, we provide a general job handling script for you to customize to your needs.
To assist with job submission script customization, example input files are available under the
$SILCSBIODIR/examples
folder.For SILCS, use the following commands to make sure the software is correctly installed and the job handling script is working. If you are only interested in SSFEP simulations, you may skip to the SSFEP section below.
mkdir -p test/silcs cd test/silcs cp $SILCSBIODIR/examples/silcs/p38a.pdb . $SILCSBIODIR/silcs/1_setup_silcs_boxes prot=p38a.pdb $SILCSBIODIR/silcs/2a_run_gcmd prot=p38a.pdb nproc=1If the script failed to run at the
1_setup-silcs_boxes
step, the software is not correctly installed, whereas if the script failed to run at the2a_run_gcmd
step, the job handling script needs to be edited. The job handling scripts for SILCS are:
templates/silcs/job_mc_md.tmpl
templates/silcs/job_gen_maps.tmpl
templates/silcs/pymol_fragmap.tmpl
templates/silcs/vmd_fragmap.tmpl
templates/silcs/job_cleanup.tmpl
Typically the header portion of the job submission script requires editing. Please contact support@silcsbio.com if you need assistance.
For SSFEP, use the following commands to make sure the software is correctly installed and the job handling script is working.
mkdir -p test/ssfep cd test/ssfep cp $SILCSBIODIR/examples/ssfep/* . $SILCSBIODIR/ssfep/1_setup_ssfep prot=4ykr.pdb lig=lig.mol2 $SILCSBIODIR/silcs/2_run_md_ssfep prot=4ykr.pdb lig=lig.mol2 nproc=1If the script failed to run at the
1_setup_ssfep
step, the software is not correctly installed, whereas if the script failed to run at the2_run_md_ssfep
step, the job handling script needs to be edited. The job handling scripts for SSFEP are:
templates/ssfep/job_lig_md.tmpl
templates/ssfep/job_prot_lig_md.tmpl
templates/ssfep/job_dG.tmpl
Typically the header portion of the job submission script requires editing. Please contact support@silcsbio.com if you need assistance.
I don’t have a cluster but I have a GPU workstation. What can I do?¶
You may be able to practically run the SilcsBio software if your GPU workstation has sufficient resources. An appropriate workstation may have at least 24 CPU cores, 4 GPUs, 64 GB of RAM, and 10 TB of disk space. Installing a job queueing system, such as the Slurm Workload Manager, will allow the SilcsBio server software to run on the workstation.
The SilcsBio Workstation is a turn-key GPU workstation hardware+software solution developed by SilcsBio that comes with all necessary software pre-installed. The SilcsBio workstation has a quiet, sleek form factor for use in an office setting and comes ready to plug in to a standard wall electrical socket. Please contact info@silcsbio.com for details.
I compiled my GROMACS with MPI and my job is not running¶
Please contact us so we can repackage the files with the appropriate command using
mpirun
instead.Alternatively, you may edit the job handling script to edit the GROMACS command.
For example, the
mdrun
command is specified at the top oftemplates/ssfep/job_lig_md.tmpl
file:mdrun="${GMXDIR}/gmx mdrun -nt $nproc"You may edit this to
mdrun="mpirun -np $nproc ${GMXDIR}/gmx mdrun"
GROMACS on the head node does not run because the head node and compute node have different operating systems¶
In this case, we recommend compilng GROMACS on the head node and compiling
mdrun
only on the compute node.Building only
mdrun
can be done by supplying the-DGMX_BUILD_MDRUN_ONLY=on
keyword to thecmake
command in the build process. Once themdrun
program is built, place it in the same $GMXDIR folder. Now template files needs to be edited to use themdrun
command properly on the compute node.For example, the
mdrun
command is specified at the top of thetemplates/ssfep/job_lig_md.tmpl
file:mdrun="${GMXDIR}/gmx mdrun -nt $nproc"You may edit this to
mdrun="${GMXDIR}/mdrun -nt $nrpoc"
I want to modify the force field and topology files for SILCS simulation¶
As an example, if there is the need to add extra bonds that are not present in the standard force field definitions, this is the procedure to make the necessary modifications. For example, some proteins contain two metals ions adjacent to each other, in which case it may be useful to place a bond connecting the ions. The protein 3bi0 has two Zn ions adjacent to each other, and adding such a bond is useful to restrain the distance between the ions to that in the crystal structure. Please refer to the GROMACS documentation regarding to modify the .top and ffbonded.itp files.
First, run the following command. This will copy the basic force field to and generate an initial topology file in
1_setup/
, allowing you to edit them.$SILCSBIODIR/silcs/1_setup_silcs_boxes prot=<prot PDB>Then edit the force field parameter file
1_setup/charmm36.ff/ffbonded.itp
.If you want to modify the topology file (e.g. to add an explicit bond between the ions), copy
1_setup/<prot>_gmx.top.1.bak
to1_setup/<prot>_gmx.top
. Then edit<prot>_gmx.top
and add the desired bond between the two ions in the[ bond ]
list.Once the files are edited, re-run the 1_setup command with the
skip_pdb2gmx=true
keyword. This will preserve your edits and create the necessary files to run the SILCS simulations.$SILCSBIODIR/silcs/1_setup_silcs_boxes prot=<prot PDB> skip_pdb2gmx=trueOnce this completes, run the
$SILCSBIODIR/silcs/2a_run_gcmd
script to initiate your SILCS simulations.
I want to visualize FragMaps using MOE¶
By default, SILCS FragMaps are in the MAP grid file format. However, this file format is not supported in MOE. Please see FragMaps in MOE for detailed instructions on how to visualize FragMaps using MOE.
How do I handle phosphorylated amino acids?¶
The following phosphorylated amino acids are supported:
pSer
pThr
pTyr
To create a phosphorylated amino acid, rename that amino acid in your input pdb file as follows:
SER => SP1 or SP2
THR => THP1 or THP2
TYR => TP1 or TP2
The number at the end of the amino acid name refers to whether the phosphate group has mono- or divalent charge.
What if my protein has a glycan attached to it?¶
While setting up a glycan-containing protein directly from a PDB file is not currently supported, you can set up your simulation system for SILCS if you have a PSF file created with the CHARMM36 force field.
An example can be found in the
$SILCSBIODIR/examples/glycan
folder. Running thesetup.sh
script in that directory will run the example and create a folder named1_setup
.For your own system, copy the
gromacs
folder andsetup.sh
file and edit the copiedsetup.sh
file before running it:psffile="psf/step1_pdbreader.psf" # PSF file pdbfile="psf/step1_pdbreader.pdb" # PDB file prefix="5vgp" # prefix for the SILCS simulation