The Chimera Viewer
Since Jalview 2.8.2, Chimera
(http://www.cgl.ucsf.edu/chimera/) can be used for viewing
structures opened via the "View
Structure Data.." dialog.
You can set a default choice of Jmol or Chimera structure viewer in
Preferences. You can also
optionally specify the path to the Chimera program here (if it
differs from the standard paths searched by Jalview).
Please
make sure your version of Chimera is up to date. Jalview requires
at least Chimera version 1.11.1
If you save your Jalview session as a project file, the state of any
open Chimera windows will also be saved, and can be reopened by
loading the project file on any machine with Chimera installed. Since
Jalview 2.9.
Superposing structures based on
their aligned sequences
If several structures are
available on the alignment, you may add additional structures to an
existing Chimera view by selecting their entry in the appropriate
pop-up menu. Jalview will ask you if you wish to add the structure
to the existing alignment, and if you do, it will import and
superimpose the new PDB file using the corresponding positions from
the alignment. If the alignment is subsequently edited, you can use
the Chimera→Align menu option
from the menu bar of the structure view window to superpose the
structures using the updated alignment.
Chimera Controls
The structure is by
default rendered as a ribbon diagram. Moving the mouse over the
structure brings up tooltips giving the residue name, PDB residue
number and chain code ([RES]Num:Chain). Moving the mouse over an
associated residue in an alignment window highlights the associated
atoms in the displayed structures. When residues are selected in the
Chimera window, they are highlighted on the alignment.
For comprehensive details of Chimera's commands, refer to the
tool's Help menu.
Selecting residues in Jalview from Chimera
When a selection is highlighted in a Jalview window, use the
Select→Select Highlighted Region or press B
to add the mapped positions to the alignment window's column
selection.
Hint: Use your machine's 'switch
application' key combination (Alt-Tab on Windows and Linux,
Cmd-Tab on OSX) to quickly switch between UCSF Chimera and Jalview
before pressing 'B' to select highlighted regions.
Basic screen operations (see Chimera
help at
http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/mouse.html
for full details).
Action |
Windows |
Unix |
Mac/OSX |
Rotate View |
Left Click and Drag |
Left Click and Drag |
Left Click and Drag |
Zoom |
Right Click drag mouse up or down
|
Right Click drag mouse up or down
|
cmd or Right + Click and drag mouse up or down, or
use mouse scroll button
|
Move Origin |
Middle Button + Drag |
Middle Button and drag |
alt + Click and drag
|
Select Residues |
Ctrl + Click (and drag to select a region) |
Ctrl + Click (and drag) |
Ctrl + Click (and drag) |
Jalview Controls
The Jalview Chimera View window has up to five menus:
- File
- View Mapping
Opens a text window showing the alignment between the
residues corresponding to alpha-carbon atoms in the PDB
structure and the residues in the associated sequence.
- View
- Show Chains
Select which of the PDB file's chains (if more than
one) are to be displayed.
- Colour by ..
Submenu
allowing specific alignment views to be selected for
colouring associated chains in the structure display. This
menu contains all the alignment views associated with the
structure view, with those used to colour the view indicated
by ticks. Addditionally, it contains the following menu
entries:
- Select many views
When
this option is enabled, selecting an alignment view adds
it to the set used to colour the structures. Use this
when colouring structures related to a number of
alignments involving different domains or chains which
are shown in the same structure view.
- Select all views
This
is only enabled when Select many views
is also enabled, and will add all associated views to
the set used to colour the structure display.
- Invert selection
This
is only enabled when Select many views
is also enabled, and will replace the current set of
views with any remaining views not currently used to
colour the structure display.
- Colours
- By Sequence
Colours each residue in the structure with the colour
of its corresponding residue in the associated sequence as
rendered in the associated alignment views, including any
UniProt sequence features or region colourings.
Pick
which of the associated alignment views are used to colour
the structures using the View→Colour
by .. sub menu.
Residues which only exist in the PDB structure are
coloured white if they are insertions (relative to the
associated sequence in the alignment) and grey if they are N
or C terminal flanks outside the region mapped to the
alignment window's sequence.
- By Chain
Uses the Chimera 'rainbow chain' command to apply a
different colour to each chain.
- Charge & Cysteine
Highlights cysteines in yellow, anionic (Aspartic Acid
or Glutamic Acid) residues in red, and cationic (Lysine or
Arginine) residues in blue.
- Colour with Chimera
Defers
any colouring operations to Chimera. Select this if you want
to use the Chimera scripting interface or menu to modify the
view directly.
- Standard and User Defined Jalview
colourschemes.
The remaining entries apply the colourschemes available
from the standard and user defined amino acid
colours.
- Chimera
This pulldown menu is only displayed if there are multiple
structures shown in the Chimera window, and Jalview can also
locate at least two of the structures in the currently
associated alignment view.
- Align
When selected, the associated alignment will be used to
superimpose all the structures in the view onto the first
structure in the alignment. The regions used to calculate
the superposition will be highlighted using the 'Cartoon'
rendering style, and the remaining data shown as a chain
trace.
- Help
- Chimera Help
Access the Chimera Help documentation in a new browser
window.
Chimera and Windows Firewall
Jalview and Chimera communicate using Chimera's
REST
service
(http://www.cgl.ucsf.edu/chimera/current/docs/ContributedSoftware/restserver/restserver.html).
Technically this requires both Chimera and Jalview to open
ports on the local network, and this may be blocked by Windows
Firewall with a warning message such as
"Windows Firewall has blocked some features of this program"
(where the program may be jp2launcher.exe for Jalview Webstart, or
java.exe or javaw.exe for the InstallAnywhere version).
To allow Jalview and Chimera to interact, you may need to add
permission for the program to communicate over the network. This can
be done from the warning dialogue, or in Control Panel, Firewall
settings.