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. Commercial users, please see Chimera commercial licensing.

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

Orexin Receptor Complex

The image shows the structure of the human OX2 orexin receptor bound to the insomnia drug suvorexant, Protein Data Bank entry 4s0v. The drug is shown as spheres colored by element, and the receptor as ribbons with secondary structure elements rainbow-colored from blue at the N-terminus to red at the C-terminus. (More samples...)