I have a 4306 and currently have my tsu7500 set up for seven speaker surround. However, at our old house, I did have zone two enabled.
To run zone one, I had my pcf set to just turn on zone one. There are separate code sets for zones 1, 2 and 3. I believe that there might be a code that turns all three zones on at the same time, but I really can't be certain as I never wanted that function. As you know, the Denons are highly configurable, as are the Prontos. When you mix the two, the permutaions for setting them up are virtually endless.
Just go into your pcf and check which codes are being used when you turn on your Denon.
I got the discrete codes for the Denon from the files on this site and used them. I believe I used the codes from someone's 3806 configuration and they work fine for my 4306, so you should have no problem.
Good luck,
Rick