UCSF Chimera is a program for the interactive visualization and analysis of molecular structures and related data, including density maps, trajectories, and sequence alignments. High-quality images and animations can be generated. Chimera includes complete documentation and is free of charge for academic, government, nonprofit, and personal use. Chimera development was supported by the National Institutes of Health (P41-GM103311).

UCSF ChimeraX is the next-generation molecular visualization program from the RBVI, following UCSF Chimera. We encourage Chimera users to try ChimeraX for much better performance with large structures, as well as other major advantages. ChimeraX replaces a significant subset of Chimera features, includes several completely new features, and is under active development. Users may certainly choose to use both programs, and it is fine to have both installed.

Feature Highlight

Sequence Viewer

The Multalign Viewer tool displays individual sequences and multiple sequence alignments. Sequence alignments can be read from external files (several formats) or created by other tools in Chimera. Structures opened in Chimera are automatically associated with sufficiently similar sequences in the alignment. After association,

• mousing over a residue in the sequence shows its structure residue number
• selecting in the sequence selects residues in the structure(s) and vice versa
• structures can be superimposed using the sequence alignment

Various measures of sequence conservation and structural variation (RMSD) can be computed and shown above the sequences as histograms, and on the structures with color or worm radius. Secondary structure elements can be depicted as colored boxes or regions on the alignment. Regions can also be created by hand.

(More features...)

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Gallery Sample

Wasabi Receptor

The image shows the structure of the human TRPA1 ion channel (wasabi receptor) determined by electron cryo-microscopy, Protein Data Bank entry 3j9p. The four subunits of the tetramer are shown as ribbons in different colors over a dark-to-light gradient background. (More samples...)