New to NL, AKo, push or fold?

[PokerDork]

I typicallly play live limit poker, generally 5/10 and 10/20, but yesterday I was sort of feeling like playing a little NL. My local casino (Potawatomi) spreads a $3/$5 that's basically a $200min/$400max. Being relaitvely new to NL I bought in for $200 and figured I'd add-on the other two if I felt comfortable at the table, and if not, probably take the nice soft seat in the 5/10 across the room. Anyway, nothing much had happpened for me to this point, and after losing a couple small pots and winning a couple small pots I had a little over $200 in front. Villain seems to be a little weak-tight, and playing timidly, I haven't seen him re-raise a pot in a couple of hours. Anyway, I'm UTG+1 with the A [img]/images/graemlins/spade.gif[/img]K [img]/images/graemlins/club.gif[/img].

UTG limps, I raise to $25, folds to button who raises to $100.
It folds around to me. Is this an easy push (I only have ~$175 left), or should I be folding?

[jkkkk]

If hes weak-tight, fold.