OBP sequences and structures.

<p>(A) The multi-sequence alignment for OBPs, 3BFH (PBP from honeybee <i>Apis mellifera</i>), 3OGN (OBP from the malaria mosquito <i>Anopheles gambia</i>), 1P28 (PBP from the cockroach <i>Leucophaea maderae</i>) and 1DQE (PBP from the silkmoth <i>Bombyx mori</i>). They represented the OBPs with different length of chain. The main difference of these OBPs is the length of C-terminal loop: 1DQE has a long <i>C</i>-ter, 1P28 has no <i>C</i>-ter while 3BFH and 3OGN have a mediate long <i>C</i>-ter. (B) The structure alignment for the above OBPs. Though they have low sequence similarity, they share almost identical tertiary structures, which imply that they share the same operating mechanism and dynamics. Three conserved disulfide bonds are shown as ball-and-stick models in yellow color. (C) The structure of palmitic acid, a typical odorant ligand.