Flopped straight. What to do at the turn?

[Duffman]

Villain is a bit loose that's all I have on him so far.

Party Poker No-Limit Hold'em Tourney, Big Blind is t20 (10 handed) converter

UTG (t960)
UTG+1 (t1440)
UTG+2 (t715)
MP1 (t1850)
Hero (t1680)
MP3 (t930)
CO (t142)
Button (t815)
SB (t1725)
BB (t1000)

Preflop: Hero is MP2 with A[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#666666">4 folds</font>, Hero calls t20, <font color="#666666">1 fold</font>, CO calls t20, Button calls t20, <font color="#CC3333">SB raises to t40</font>, BB calls t20, Hero calls t20, CO calls t20, Button calls t20.

Flop: (t200) K[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">SB bets t200</font>, BB folds, <font color="#CC3333">Hero raises to t500</font>, Button folds, SB calls t300.

Turn: (t1200) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB Bets 1185(All-in)</font>, Hero??