Melo's size and measurables were a big reason he went 22. There's no question he has the size to be a good NBA center.
He has true NBA size and better than average athleticism compared to true centers. Syracuse players have had a tough time transitioning tot he NBA because they play almost no man to man defense there, but for a true center, being able to play the Cuse zone effectively tells me he has the lateral movement needed to play NBA defense.
Melo can learn the bump and grind stuff and has good feet and a good lower body, which, along with his size, standing reach, and no step vert, should make him a good candidate to be a solid one on one low post defender.