Ok then the best way is to make a homology model using at least 2 softwares.
The best one available are iTasser and Swiss Model. Given that it is drosophila, many templates will be available. If you need help with the interpretation of results , feel free to contact
Thank you for the suggestion. Although templates with good sequence identity are not available for insect olfactory receptors. Also iTasser predicts a structure which does not support experimental observations. I will give a try to Swiss Model.
The experimentalists have proven that the insect olfactory receptors possess 7 transmembrane helices with big loops. iTasser predicts 9 to 12 helices with small loops. So it does not seem to be coherent.
I would like to suggest you RaptorX (http://raptorx.uchicago.edu/StructurePrediction/predict/) structure modeling, or Modller (loop modeling and optimization). MODWEB server.
Using Multi-template and selection of suitable template was best in Raptor X.