Multipe Sequence Alignments:
Identifying an enzyme active site

  1. Identifying a conserved domain

    • 1-In the following BLAST output we selected cfad_human(P00746), cfad_pig (P51779), graa_human(P12544), cap7_human(P20160) , catg_human(P08311), try2_human(P07478), try2_xenla(70059), try1_salsa in order to obtain the following alignment. Conserved Serines are good candidates for being part of the active site. Conserved aromatics are more likely to be involved in the structure
    • 2-We now add an extra sequence: cap7_human (P20160) that does not seem to have any catalytic activity but is unquestionably a member of the family. This helps pointing out residues whose mutation in CAP7 are good candidate for being responsible for the loss of function (You could also use the Haptoglobins). This gives the following alignment.

    • Conclusion:Distant sequences that are well caraterized make it possible to propose very detailed hypothesis regarding enzyme mechanisms.

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