While Ake did get plaudits for his performances with Bournemouth, his side were relegated from the Premier League this season.
City have secured the Dutch star's signature, and Begiristain believes playing with some of the best players in the world will elevate Ake's game.
He told the club website: "Nathan is a quality defender. He was a leader during his time at Bournemouth, and I am so pleased we've managed to bring him here.
"He's strong and quick, and we feel he has the technical and intellectual attributes needed to excel in Pep's setup.
"Working with this squad, which is full of world-class players, will raise his level, and we are looking forward to seeing what he can achieve here in the coming years."