NMR Information Server

   MARS is a program for robust automatic backbone assignment of ¹³C/¹⁵N labeled proteins. It can be applied independent of the assignment complexity, it does not require tight thresholds for establishing sequential connectivity or detailed adjustment of these thresholds, it can work with a wide variety of NMR experiments and it is robust against missing chemical shift information.

Compared to other currently available programs MARS is applicable to proteins above 15 kDa using only Ca and Cb chemical shift information with connectivity thresholds as high as 0.5 ppm and it is applicable to proteins with very high degeneracy such as partially or fully unfolded proteins. It offers improved assignment scores for proteins where data are missing for a substantial portion of residues and it has a good tolerance against erroneous chemical shifts. In case of a known 3D structure, residual dipolar couplings can be used to enhance assignment.

MARS assignment results can be directly read into the program SPARKY. This allows visual validation of the assignment results. Thus, several cycles of automatic assignment using MARS and manual validation on the screen can be performed, in order to complete assignment even in difficult cases.

MARS can be downloaded at
          http://www.mpibpc.gwdg.de/abteilungen/030/zweckstetter

Further information can be found in

J. Biomol. NMR, 30, (2004), 11-23       and
J. Biomol. NMR, 30, (2004), 25-35.

For comments or questions please contact

Markus Zweckstetter
Max Planck Institute for Biophysical Chemistry
Am Fassberg 11
37077 Goettingen
Germany
Email: mzwecks@gwdg.de