NL $50: TPTK facing turn shove

[Crizby]

The Villain in this hand is 63/4/1.5 and have seen him splash around a lot.

Cryptologic
No Limit Holdem Ring game
Blinds: $0.25/$0.50
6 players
Converter

Stack sizes:
UTG: $39.50
UTG+1: $87
Hero: $46.30
Button: $60.80
SB: $41.78
BB: $40.34

Pre-flop: (6 players) Hero is CO with K[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/spade.gif[/img]
UTG folds, UTG+1 calls, <font color="#cc0000">Hero raises to $2.5</font>, 2 folds, BB calls, UTG+1 folds.

Flop: 7[img]/images/graemlins/club.gif[/img] 3[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/club.gif[/img] ($5.75, 2 players)
BB checks, <font color="#cc0000">Hero bets $4</font>, BB calls.

Turn: 3[img]/images/graemlins/club.gif[/img] ($13.75, 2 players)
<font color="#cc0000">BB is all-in $33.84</font>, Hero?.

One thing to note is as soon as the club came on the turn he insta pushed, im never sure what to do in this situation, any help appreciated.