International
Tables for
Crystallography
Volume B
Reciprocal space
Edited by U. Shmueli

© International Union of Crystallography 2006
International Tables for Crystallography (2006). Vol. B. ch. 3.3, p. 382   | 1 | 2 |

Section 3.3.3.2.4.  MMS-X

R. Diamonda*

aMRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, England
Correspondence e-mail: rd10@cam.ac.uk

3.3.3.2.4. MMS-X

| top | pdf |

The Molecular Modelling System-X (MMS-X) is a system of purpose-built hardware developed by Barry, Marshall and others at Washington University, St Louis. Associated with it are several sets of software. The St Louis software consists of a suite of programs rather than one large one and provides for the construction of a polymer chain in helical segments which may be adjusted bodily to fit the electron density, and internally also if the map requires this too. Non-helical segments are built helically initially and unwound by user-controlled rotations in single bonds. The fitting is done to visual criteria. An example of the use of this system is given by Lederer et al. (1981[link]).

Miller et al. (1981[link]) have described an alternative software system for the same equipment. Functions invoked from a keyboard allow dials to be coupled to dihedral angles in the structure. Their system communicates with a mainframe computer which can deliver small blocks of electron density to be contoured and stored locally by the graphics system; this provides freedom of choice of contour level at run time. An example of the use of this system is given by Abad-Zapatero et al. (1980[link]).

References

First citation Abad-Zapatero, C., Abdel-Meguid, S. S., Johnson, J. E., Leslie, A. G. W., Rayment, I., Rossmann, M. G., Suck, D. & Tsukihara, T. (1980). Structure of southern bean mosaic virus at 2.8 Å resolution. Nature (London), 286, 33–39.Google Scholar
 First citation Lederer, F., Glatigny, A., Bethge, P. H., Bellamy, H. D. & Mathews, F. S. (1981). Improvement of the 2.5 Å resolution model of cytochrome b562 by re-determining the primary structure and using molecular graphics. J. Mol. Biol. 148, 427–448.Google Scholar
 First citation Miller, J. R., Abdel-Meguid, S. S., Rossmann, M. G. & Anderson, D. C. (1981). A computer graphics system for the building of macromolecular models into electron density maps. J. Appl. Cryst. 14, 94–100.Google Scholar








































to end of page
to top of page