AKo TPTK; happy getting it all in?

[elstunar]

Just after the first break in 4/180. The BB has been pretty solid only showing down pretty good hands so far showing down good hands so far. Table has been pretty tight as of late. What do you put the BB on here and what's ur plan after this?

PokerStars No-Limit Hold'em Tourney, Big Blind is t150 (9 handed) internettexasholdem.com

CO (t3405)
Button (t1625)
SB (t3615)
BB (t8940)
Hero (t4120)
UTG+1 (t1260)
MP1 (t6935)
MP2 (t4550)
MP3 (t2520)

Preflop: Hero is UTG with A[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/heart.gif[/img].
<font color="#CC3333">Hero raises to t450</font>, <font color="#666666">5 folds</font>, Button calls t450, <font color="#666666">1 fold</font>, BB calls t300.

Flop: (t1425) 2[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">Hero bets t1050</font>, <font color="#CC3333">Button raises to t1175</font>, BB calls t1175, Hero ???