MSMS
MSMS computes, for a given set of spheres S and a probe radius rp, the Reduced Surface and the analytical model of the Solvent Excluded Surface (SES). The SES can then be triangulated with a given vertex density. It was written by Michel F. Sanner at The Scripps Research Institute, La Jolla, California.
ABSTRACT: Because of their wide use in molecular modeling, methods to compute molecular surfaces have received a lot of interest in recent years. However, most of the proposed algorithms compute the analytical representation of only the solvent-accessible surface. There are a few programs that compute the analytical representation of the solvent-excluded surface, but they often have problems handling singular cases of self-intersecting surfaces and tend to fail on large molecules (more than 10,000 atoms). We describe here a program called MSMS, which is shown to be fast and reliable in computing molecular surfaces. It relies on the use of the reduced surface that is briefly defined here and from which the solvent-accessible and solvent-excluded surfaces are computed. The four algorithms composing MSMS are described and their complexity is analyzed. Special attention is given to the handling of self-intersecting parts of the solvent-excluded surface called singularities. The program has been compared with Connolly's program PQMS [M.L. Connolly (1993) Journal of Molecular Graphics, Vol. 11, pp. 139-141] on a set of 709 molecules taken from the Brookhaven Data Base. MSMS was able to compute topologically correct surfaces for each molecule in the set. Moreover, the actual time spent to compute surfaces is in agreement with the theoretical complexity of the program, which is shown to be O[n log(n)] for n atoms. On a Hewlett-Packard 9000/735 workstation, MSMS takes 0.73 s to produce a triangulated solvent-excluded surface for crambin (1 crn, 46 residues, 327 atoms, 4772 triangles), 4.6 s for thermolysin (3tln, 316 residues, 2437 atoms, 26462 triangles), and 104.53 s for glutamine synthetase (2gls, 5676 residues, 43632 atoms, 476665 triangles).[1]
Usage
Note: The program can run in standalone or server mode - if filename). In server mode, the only requested option is the socket name to be used to communicate with the client application (-socket servicename or -sinetd).
msms [ -if filename ] [ -of filename ] [ -af filename ] \
[ -probe_radius radius ] [ -density density ] [ -no_area ] \
[ -surface <tses,ases> ] [ -socket servicename ] [ -sinetd ] \
[ -noh ] [ -no_rest_on_pbr ] [ -no_rest ] \
[ -free_vertices ] [ -all_components ] \
[ -one_cavity #atoms at1 [at2] [at3] ] [ -no_header ]
Example
Note: The input file must have four columns: x, y, z (from a PDB structure) and r (radius).
msms -if foo.xyzr > foo.ses
References
- ↑ Sanner MF, Olson AJ, Spehner JC (1996). "Reduced surface: an efficient way to compute molecular surfaces". Biopolymers, 38(3):305-20. PMID: 8906967.
