Figure 2

Selection pressures on amino acids in each of the six clusters analyzed. In each cluster the forkhead domain position was obtained from the NCBI Entrez Protein [11] database record for that sequence (see Additional file 1 for accession numbers). A. FoxA cluster of 31 sequences. Peach: conserved domain IV, site 1 [36, 74] Blue: conserved domain V, sites 2–7 [36, 74] Green: forkhead domain, sites 25–101 Yellow: conserved domain II, sites 147–160 [72] Pink: conserved domain III, sites 174–177 [72] Black Bar: nuclear localization signal, sites 19–32 and 88–101 [74] Red Bar: EH1 motif, sites 151–160 [33, 34]B. FoxD cluster of 24 sequences. Green: forkhead domain, sites 42–119 Acidic and alanine/proline rich regions described by Ernstsson et al. 1996; Sutton et al. 1996; Ernstsson et al. 1997; Freyaldenhoven, Fried, and Wielckens 2002. Red Bar: EH1 motif, sites 163–169 for all of the FOXD4s, sites 176–186 for FOXD1 and FOXD3 [33, 34]C. FoxI cluster of 10 sequences. Green: forkhead domain, sites 123–200 Yellow: transactivation domain, sites 196–282 [78]D. FoxO cluster of 12 sequences. Green: forkhead domain, sites 61–141 Orange: nuclear export signal, sites 1–43 and 235–264 for FOXO1a, sites 244–252 and 258–266 for FOXO3a, sites 250–256 for FOXO4 [42, 46, 47, 76] Black Bar: nuclear localization signal, sites 52–60 and 134–180 for FOXO1a, sites 152–154 and 173,174 for FOXO3a, sites 144–183 for FOXO4 [42, 45, 46] Yellow: transactivation domain, sites 389–428 for FOXO1a, sites 221–326 and 378–428 for FOXO4 [38, 39] Blue Bar: phosphorylation site, sites 20, 157 and 216 for FOXO1a, FOXO3a and FOXO4, additionally site 218 for FOXO1a, sites 379 and 383 for FOXO4 [44, 48–52, 55, 56]E. FoxP cluster of 10 sequences. Purple: glutamine rich region, sites 6–182 [58, 61, 79–81] Blue: zinc finger, sites 288–311 [58, 60, 61, 81] Yellow: leucine zipper, sites 324–349 [58–61] Green: forkhead domain, sites 434–506 Grey Bar: region involved in repression, sites 1–505 [59, 80] Red Bar: EH1 motif, sites 398–408 and 501–511 for FOXP1, sites 501–511 for FOXP2.