Sulfur single-wavelength anomalous diffraction crystal structure of a pheromone-binding protein from the honeybee Apis mellifera L.
Pheromone binding proteins (PBPs) are small helical proteins ( approximately 13-17 kDa) present in several sensory organs from moth and other insect species. They are involved in the transport of pheromones from the sensillar lymph to the olfactory receptors. We report here the crystal structure of a PBP (Amel-ASP1) originating from the honey-bee (Apis mellifera) antennae and expressed as recombinant protein in the yeast Pichia pastoris. Crystals of Amel-ASP1 were obtained at pH 5.5 using the nano-drops technique of crystallization with a novel optimization procedure, and the structure was solved initially with the single-wavelength anomalous diffraction technique using sulfur anomalous dispersion. The structure of Amel-ASP1 has been refined at 1.6-A resolution. Its fold is roughly similar to that of other PBP/odorant binding proteins, presenting six helices and three disulfide bridges. Contrary to the PBPs from Bombyx mori (Sandler, B. H., Nikonova, L., Leal, W. S., and Clardy, J. (2000) Chem. Biol. 7, 143-151) and Leucophea maderae (Lartigue, A., Gruez, A., Spinelli, S., Riviere, S., Brossut, R., Tegoni, M., and Cambillau, C. (2003) J. Biol. Chem. 278, 30213-30218), the extended C terminus folds into the protein and forms a wall of the internal hydrophobic cavity. Its backbone groups establish two hydrogen bonds with a serendipitous ligand, n-butyl-benzene-sulfonamide, an additive used in plastics. This mode of binding might, however, mimic that used by one of the pheromonal blend components and illustrates the binding versatility of PBPs.
Lartigue
Audrey
A
Architecture et Fonction des Macromolécules Biologiques, Unite Mixte de Recherche 6098 CNRS and Universités Aix-Marseille I and II, 13402 Marseille Cedex 20, France.
Gruez
Arnaud
A
Briand
Loïc
L
Blon
Florence
F
Bézirard
Valérie
V
Walsh
Martin
M
Pernollet
Jean-Claude
JC
Tegoni
Mariella
M
Cambillau
Christian
C
D000818:Animals; D001516:Bees / Q000737:chemistry / Q000235:genetics; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics; D003460:Crystallization; D018360:Crystallography, X-Ray; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D055672:Static Electricity; D013455:Sulfur / Q000737:chemistry
D002352:Carrier Proteins; D019476:Insect Proteins; D011994:Recombinant Proteins; C403713:pheromone binding protein, insect; D013455:Sulfur