MutInf

 

What is MutInf?

 

MutInf is an analysis package written in Python. inline C, and R that analyzes data from Molecular Dynamics Simulations to identify statistically significant correlated motions and calculate residue-by-residue conformational entropies. Our work has shown that the pattern of mutual information between residues can be used to identify couplings between allosteric sites and identify residues that might be important in mediating these couplings.

 

Obtaining MutInf

 

MutInf is free for academic use. It will most likely be put under tPlease contact Chris McClendon if you would like a copy of the code.

 

If you use MutInf, please cite:

 

Christopher L. McClendon, Gregory Friedland, David L. Mobley, Homeira Amirkhani, Matthew P. Jacobson. Journal of Chemical Theory and Computation. 2009, 5 (9), pp 2486–2502.

 

The code works best with Python 2.4.4 or 2.6.2, and requires NumPy and SciPy libraries, which take a bit of work to install but are well-worth the effort. Alternatively, Schrodinger (http://www.schrodinger.com) bundles NumPy and SciPy with their Maestro package, which is free for academics.

 

I recommend running MutInf on 64-bit machines with as much RAM is possible -- ideally 4GB-16GB.

One requirement of the method is that you have many thousands of trajectory snapshots, ideally many tens of thousands. For six simulations of 10 ns each, ideally you'd want to save snapshots every 0.5ps -- 1ps, though the method will still work fine (but may reject some correlations as not statistically significant) if you have snapshots every 10 ps, though this is not recommended, unless your simulations are longer (i.e. 100ns). In Mike Gilson's papers that I cite, he keeps more snapshots than I do, up to every 100fs. I use robust entropy estimators and statistical filters that allow smaller sample sizes, so one can use thousands to tens if thousands of snapshots instead of a million or more snapshots.

 

Acknowledgements

 

A very special thanks to Greg Friedland for helping with code development and debugging. Without his help the code would not be what it is today. Thanks also to Salma Rafi for being the first end-user of the code and for using it in biologically-impactful applications, and to Adam Steeves who is currently improving the clustering/analysis protocol. Finally, thanks to my advisors, Matt Jacobson and Jim Wells, for supporting and encouraging my study of allostery and the development of this software.

 

Repository Access

 

MutInf's repository is on the SimTK site ( https://simtk.org/home/mutinf ), where a number of other useful simulation analysis tools can be found. Please contact Chris McClendon (see Contact below) if you have any suggestions, bug reports, patches, new features, etc.

 

MutInf Manual

 

1.    Installation

2.    Getting dihedral angles from simulations

3.    Specify residues to analyze

4.    Organize files into MutInf’s official directory structure

5.    Running the program (and options)

6.    Analyzing the results (and output files)

7.    Helpful utilities

8.    Contact