I just made my very first batch of jerky yesterday. I used cure #1 because I had it on hand and DaveOmak had it in his recipe. Alton Brown, who posted the original recipe online did not have cure in his jerky. I first learned about making jerky about four decades ago in survival training, and there was no salt or anything, just heat, smoke, and moving air.
Dave will probably be along and educate us both on your question, but my guess is cure is not necessary. It is just an additional safety factor. My wife likes her jerky softer, so I will definitely be adding cure for the safety.