Friday, June 6, 2014

A new online viewer for multiple alignments

For my work on the alignment of coiled-coil proteins, I needed an alignment viewer that could highlight coiled-coil domains, since they contain less phylogenetic signal than other parts of the protein. Adding this to JalView seemed very complicated, and not possible at all in other web-based viewers like MView. I therefore created amview (for "annotated multiple alignment viewer"), which looks like this in practice:

Shown is the MSA for spd-5 (and here is the entry in my coiled-coil orthologs database). Amino acids are colored according the ClustalW rules, coiled-coil residues are in a lighter color (and the "a" register of the heptad repeat is underlined). Below, two interaction domains are shown. At the very bottom, a small chart shows the degree of conservation across the whole alignment, which can be used to quickly scroll to the conserved regions. The cog on top hides two options: you can hide columns with too many gaps, and proteins that seem to be fragments.

I've only tested this thoroughly in Google Chrome, as I found other browsers to be too slow. Still, it's better than loading a Java applet, and even runs on iPhones/iPads etc.! The implementation relies on Django on the server side, and JavaScript / JQuery in the browser.