I-TASSER SUITE (Copyright 2012 by Zhang Lab, University of Michigan, All rights reserved) (Version 2.0, 2012/9/20) What is new in I-TASSER V2.0 compared to I-TASSER V1.0? 1. Protein secondary structure prediction is improved. In I-TASSER V1.0 package, PSI-pred was used to predict secondary structure of target proteins. PSI-pred is third-party software and users need to download the program from other website, which often creates incompatiobility and mistakes in I-TASSER suite configurations. We recently developed a novel secondary structure prediction (PSSpred) by combining seven neural network predictors from different profile data and parameters. The Q3 accuracy of PSSpred is ~3% higher than that of PSI-pred. Moreover, PSSpred is seamlessly integrated with the I-TASSER Suite configurations. 2. New threading programs are integrated. LOMETS in I-TASSER V1.0 includes five threading programs for protein fold- recognition and template identification. In I-TASSER V2.0, three new threading programs with a novel sequence profile generation stratagy are added. This helps I-TASSER to detect more broad range of structure templates for the I-TASSER fragment assembly. Accordingly, the average TM-score of the final models in I-TASSER V2.0 is ~5% higher than that by I-TASSER V1.0 based on the same template library. 3. More flexible for user-intervened modeling. Users sometimes have the background or structural information of their targets from experimental or biological analysis. Such information is very valuable for protein structure prediction. In I-TASSER V2.0, users are allowed to specify template, target-template aligments, residue- residue contact/distance information to guide the I-TASSER simulations. I-TASSER V2.0 also allows users to exclude specific template structures and/or the templates homologous to the target at certain distance cutoff. This is often useful for different purpose, e.g. for algorithm benchmark and comparisons. These features are newly added to I-TASSER V2.0. 4. A "light" option is added to allow faster modeling. A new option "-light" was implemented in I-TASSER V2.0, which sets the maximum time of folding simulation below 5 hours. It can be used for the users who wants quick results for large easy targets. For large hard targets, full version simulations are needed for the best results. 5. Provide an option for trajectory file deposit. Advanced users may be interesed in I-TASSER trajectory data analysis. A new option "-traj" was added in I-TASSER V2.0 to allow users to deposit structural decoys from I-TASSER simulations. 6. Fixing bugs in installation and simulations. A number of bugs in the installation and implementation, as reported by users of I-TASSER V1.0, have been fixed in I-TASSER V2.0. Please post your questions and comments at http://zhanglab.dcmb.med.umich.edu/forum.