1gcn without hydrogens 1gcn after hydrogen addition

Adding Hydrogens

Structures opened in Chimera have some basic chemical-typing information assigned to their atoms based on the IDATM algorithm developed by Meng, et al. This information is sufficient to determine basic hydrogen-addition geometries for heavy atoms. The typing information is 100% correct for nucleic acids and common amino acids (except possibly for histidine protonation state), and 90+% correct for other residue types. The ability to add hydrogens to structures based on this information has been recently implemented in Chimera. The hydrogen addition is simplistic in that it only considers the substituent geometry of the atom being added to, but is useful as long as the structure is later energy minimized.

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