The dongle as far as i know is required for the wireless xbox 360 controller (wired ones worked just plugging in).
I purchased the pc xbox one controller, and all i believe is different from a regular controller is it comes with an extra long usb cable to connect it with. My dog pulled it off my desk and the cable connector broke, so now I'm using a regular usb cable (my phones charger cable) and it's working fine. So nothing special about the cable itself.
Now if only the elite xbox one controller wasn't so expensive