Reggie Theus has his second assistant coach, according to Brian Windhorst of the Akron Beacon Journal:
Natt, whose contract with the Cavs had expired, accepted an assistant coaching position with the Sacramento Kings under new head coach Reggie Theus. Natt primarily worked with the Cavs' big men, among other duties. The Cavs are expected to look for an experienced assistant to replace Natt, who was one of coach Mike Brown's top two assistants.
Here's the official press release, which notes Natt played with Reggie for the 84-85 Kansas City Kings.
I expect Natt will coach the Kings summer league team, while it's been stated Theus will run the practices. Jason Hamm -- who was a video coordinator under Mike Fratello two years ago and an assistant under Eric Musselman last year -- is also down with the team.