The evolutionary origin of the Runx/CBFbeta transcription factors – Studies of the most basal metazoans-1

Hed structure of their human counterparts (PDB #). The RD is depicted in blue, CBFβ in green and DNA in purple. The interacting residues are depicted as ball and stick models, and colored according to their conservation with their human counterparts (Yellow = identical, Orange = conservative substitution, Red = non-conservative substitution). For clarity, a similar model with the relevant residues numbered according to the Runx RD and CBFβ proteins is provided as Additional file , and detailed tables comparing the residues of all the proteins discussed can be found as Additional files , , . . All of the residues in the RD involved in DNA binding are completely conserved in . The arrow points to compensatory changes in H163 of the RD, which is replaced with C131 in . , showing a second compensatory change which involves the substitution of F153 and M106 in human with K121 and A73 in in the RD and the replacement of Q67 and S65 with H67 and T65 in CBFβ (indicated with arrow). . In the cnidarian proteins, the majority of non-conserved residues which interact with CBFβ are located at the periphery of the interacting surfaces (C, D). and particularly indicate greater sequence divergence within this domain, with non-conservative substituions not being restricted to the periphery. . Most of the functional residues are conserved between all three proteins and the human variant, with most of the non-conservative subsitutions found at the periphery of the binding face.<p><b>Copyright information:</b></p><p>Taken from "The evolutionary origin of the Runx/CBFbeta transcription factors – Studies of the most basal metazoans"</p><p>http://www.biomedcentral.com/1471-2148/8/228</p><p>BMC Evolutionary Biology 2008;8():228-228.</p><p>Published online 5 Aug 2008</p><p>PMCID:PMC2527000.</p><p>