I don't mean to be disrespectful at all to the response that you have already received, however a Turkey should be smoked at a slightly higher temperature then one would normally BBQ at. 250-300 is ideal because you can smoke and roast the bird at the same time and get a great crisp skin. I aim for about 325 in my smoker for the last 20 degrees of cooking for this reason. As an added bonus, the extra heat can then be used to bake a desert in the smoker such as an apple or pumpkin pie.
Also, the breast should be 165 at the thickest part and the thigh should be 175. Keep in mind that the turkey will continue to cook after it is taken out of the smoker and will continue to rise an additional 5-10 degrees when you let it rest for 20 minutes under a foil tent before carving. So pull the turkey when the breast reaches about 160. I know Jeff says 175 degrees, but I have Googled this and visited a lot of other blogs and sites and he is the only one i can find that suggests 175 for the breast.
Salmonella is killed off at 160 degrees. The only thing I can think of is Jeff is considering the bird is brined and can go another 10 degrees without too much moisture loss. I would not smoke an injected bird to 175 degrees as it will be dry.
Again, I do not mean ANY disrespect to other opinions or methods presented here, but if you were to cook the breast to 175 then pull the turkey, it will continue to cook and reach up to 185 degrees which means a dry chewy turkey.