The Blink database at the NCBI
The NCBI which I have blogged about before has a number of outgoing links embedded into its search results. One of these links which I use extensively is the Blink-link , which is basically a precompiled BLAST run . The BLAST link – blink exists for every annotated sequence in the database and is a great way to look at homologs to any given sequence without messing around with cutting and pasting sequences into web forms or BLAST input parameters. As easy as clicking on a link- the results come nicely laid out with all the homologs color coded by taxonomy , i.e the archaea , bacteria , fungi , plants , etc. Clicking on any graphic takes you to the pairwise alignment. Clicking on a GI ( a unique numeric ID for every sequence in the database) takes you to the BLAST results (blink) page for that GI.
This interface is very powerful and a great way to explore the sequence space for any protein. I have put together a screencast documenting one of my recent explorations you can see it on the youtube link above.
Documentation: The Blink documentation