AK in SB 3rd hand

Okay, guys. I just need a little help on this play. I'm still a little unsure of how to play this hand so, when in doubt, I raised it up. Anyway, please judge my play on this hand.

Situation - 3rd hand of a $5.50 MTT with 800+ players. I picked up AKo on the SB. There were two limpers so I raised it 5x BB. BB smooth calls and the two limpers fold.

Flop - 5h 5d 3h

Hero bets 100 into pot of 120.
Villain calls.

Turn - 5h 5d 3h Kh
Pot - 320

Hero checks.
Villain quickly bets pot.

(At this point, I figure the guy is either trying to pick up the pot or he might have a medium pocket or a crappy K. I've won a lot of pots from players who play bad kickers really hard. He actually did exactly what I wanted him to do.)

Hero reraises to 640.
Villain goes all in.
Hero calls.

I will post the outcome of this hand after I get some reads from you guys. Basically, I am trying to get some thoughts on my play throughout this hand to this point based upon what you guys can infer.

After posting the outcome, I'd also like some pointers. Thanks in advance for the thoughts.