Dear Jeff: At 1/18/05, Jeff Cohlberg wrote: >There used to be a WHAT IF web interface in which a user could submit a >PDB ID number and get back an "hadded.pdb" file with hydrogen atoms >added. This site no longer exists, and the WHAT IF software is now only >available to those who purchase it for 500 Euros (at >http://swift.cmbi.kun.nl/whatif/). > >Is there any other free software or server which can add hydrogens to a >PDB file? The almost-released PE 2.45 has an answer in its Help/Index/Glossary under hydrogen: http://www.umass.edu/microbio/chime/beta/pe_gecko/protexpl/igloss.htm#hydrogen where it refers you to the Richardson Lab MolProbity server, which adds hydrogens to proteins and nucleic acids (but not water; same as WHATIF) http://kinemage.biochem.duke.edu/molprobity/index-king.html and also gives you lots of other very useful information, including visualization of clashes, and an overall clash score, stating where your case falls among published proteins of similar resolution. PE's "Protein Structure Bioinformatics Resources" page http://www.umass.edu/microbio/chime/beta/pe_gecko/protexpl/psbiores.htm#molprobity states "MolProbity conducts a new and powerful structure validation based on all-atom contacts analysis, producing automatic corrections (rotamer flips). The flips can be inspected and accepted or rejected in a java-based Kinemage-style viewer. The corrected PDB file, containing added hydrogen atoms, is provided. For secure use, free software that performs the all-atom contacts analysis can be downloaded and run locally. The server also offers very useful Ramachandran plots (identifying residues outside the favorable regions), C-beta deviations, and rotamer analysis." MolProbity is featured in the new PE's External Resources page. At the MolProbity website, some browsers may say you cannot use KiNG even when your java is up to date -- just ignore that error. You can use KiNG if you have an up to date java (from java.com). The server cmbi.kun.nl was down in recent days but is back up. The free on-line version of WhatIF is available at http://swift.cmbi.kun.nl/WIWWWI/ also linked into PE's Bioinformatics Resources page. -Eric /* - - - - - - - - - - - - - - - - - - - - - - - - - - - Protein Explorer - 3D Visualization: http://proteinexplorer.org Workshops: http://www.umass.edu/molvis/workshop Biochem Structure Tutorials http://MolviZ.org World Index of Molecular Visualization Resources: http://molvisindex.org ConSurf - Find Conserved Patches in Proteins: http://consurf.tau.ac.il Atlas of Macromolecules: http://molvis.sdsc.edu/atlas/atlas.htm PDB Lite Macromolecule Finder: http://pdblite.org Molecular Visualization EMail List (molvis-list): http://bioinformatics.org/mailman/listinfo/molvis-list Eric Martz, Professor Emeritus, Dept Microbiology U Mass, Amherst MA US 413-545-2325/FAX 413-545-2532 http://www.umass.edu/molvis/martz - - - - - - - - - - - - - - - - - - - - - - - - - - - */