The Protein Feature Accent tool allows you to:
On the Protein Feature Accent input page, you can provide two inputs:
After you hit "Submit", the tool will display a window that provides many options:
Along the left side are buttons for various viewing options.
This is the graphical display section. You can manipulate the image in many ways:
This section displays, at the least, the amino acid sequence of the 'main' molecule chain displayed in the JSmol window, aligned with a reference sequence. If you provided a sequence or alignment, your sequence(s) will be aligned with these sequences, and the resulting alignment will be presented here. There are also controls here to show or hide the model sequence, the reference sequence, and/or the sequence(s) you provided.
This section is interactive, in the sense that you can use your mouse or other pointing device to select portions of the model sequence, and the selected amino acid residues will be 'highlighted' in the graphic in the JSmol window. Please note that the only selectable sequence in the alignment is the one from the model, since this sequence corresponds directly with the residues shown in the graphic.
In this section are controls pertaining to sequence highlighting. Here you can choose among options for how highlighting behaves in the graphic. The residue numbers of the currently highlighted residues are listed in this section. You may also type in lists of residues and have these highlighted, providing an alternative to the sequence selection method. There is also an option to highlight residues that are 'near' the residues you type in, and you can specify what 'near' means in terms of distance. Finally, if the model loaded contains multiple 'chains', i.e., sequences, a panel of checkboxes here will let you show or hide each chain individually in the JSmol window.
A set of residues can be typed in the 'Highlight residue numbers' box using
the following rules:
You can indicate an interval of residue numbers, i.e., residue numbers 112 through 123, using a dash: '112-123'.
Separate residues can be indicated with a comma-separated list: '240, 256, 258'. Spaces after commas are fine.
These two formats can be combined: '112-123, 240, 256, 258'.
The Protein Feature Accent tool identifies potential N-linked glycosylation sites (also called sequons or PNGs) that match the Nx[TS] motif, where 'x' can be any amino acid except proline. The asparagine (N) α-carbon is marked in the graphic. For a more complete analysis of glycosylation sites in your protein sequence set, try the N-GlycoSite tool.
For certain structure files, such as the SIV gp-120 protein structure 2BF1, full glycosylation structure information is present. In these cases, an option to display these carbohydrates is offered. Note that for two of the display styles, 'cartoon' (the default view) and 'rocket', these carbohydrate structures do not appear. They reappear when the view is switched to one of the other display styles.
When you submit an alignment to the tool, the Shannon entropy is calculated for each alignment column. This information can be visualized on the Jmol graphic by selecting the 'entropy' option under the menu labeled 'pick color scheme'. Zero- and low-entropy residues are colored a 'cool' color (e.g., blue-green), and higher entropy residues are shown in shades of yellow, orange, and red. Residues for which an entropy cannot be calculated (for instance, residues which correspond to an all-gap column in the alignment sequences you provide) are colored a distinctive 'cold' color (e.g., dark blue).
You can upload a Protein Data Bank model file and the tool will display your model instead of one of our stored protein models. The tool will extract and display the protein sequence from the PDB file you provide, and you can highlight residues in the graphic by selecting them as usual. If you provide a sequence or an aligned set of sequences, the tool will align the PDB file sequence to your sequence(s) and display the alignment.