I-TASSER-MR is a pipeline of automated molecular replacement (MR),
designed for solving the phase problem of distant-homology proteins
in X-ray crystallography.
Starting from the amino acid sequences, 3D models are constructed
based structural assembly simulations
where the unreliably modeled regions with high variation
are truncated by a progressive edit procedure.
Multiple seed models with different truncations are then submitted to
molecular replacement search by replica-exchange Monte Carlo simulations.
For each I-TASSER model, up to 60 copies of truncated models are
attempted and the top five solutions ranked by the free R factor of the CNS refined models are
An illustrative example of the I-TASSER-MR output can be found
For each target, the output data are kept online for three months before they are removed from the server.
I-TASSER-MR online server
- Y. Wang, J. Virtanen, Z. Xue, Y. Zhang.
I-TASSER-MR: automated molecular replacement for proteins without close homologs using iterative
fragment assembly and progressive sequence truncation,
- Y. Wang, J. Virtanen, Z. Xue, J. J. G. Tesmer and Y. Zhang. Using iterative fragment assembly and progressive sequence truncation to facilitate phasing and crystal structure determination of distantly related proteins. Acta Cryst. (2016). D72, 616-628
[PDF] [Support Information]