Need more information than that to really say...
Any type of read on this player? Is it common for him to do this on the button? Have you seen him raise here and then get reraised? If so what did he do?
You are getting very late in the tournament and players should be getting more aggressive by now. You also with 5 left have presumably seen this guy play more than a couple of hands.
So the above info would dictate exactly how i played the hand, but in that general situation with no reads his raising range includes a whole lot of hands that are inferior and/or coin flip type vs AKs so I would say reraise. How much depends on what I've seen the player do, but you are most likely ahead.
Remember even though he has you covered his stack is about the same as yours and the odds
are just too good you have a far superior hand.
About the only reason for playing conservatively here is if moving up another spot is worth alot more money (or going from the bubble to the money) which is why I asked about payouts. Even then I don't really like conservative play here if you are on the bubble you could just call and see what flops/what he does post flop.