Nut straight facing river overshove 3/6nl

[jaywks]

Villain here is kinda donkish. He's 37/11/1 but with a river aggression of 3. I've seen him overvalue some hands and stuff, but I don't really have a real good read on him.

What do you do on the river?

Poker Stars, $3/$6 NL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

SB: $1,656.65
BB: $721.25
UTG: $369
MP: $630.25
CO: $646
Hero (BTN): $1,955.50

Pre-Flop: 8[img]/images/graemlins/club.gif[/img] T[img]/images/graemlins/club.gif[/img] dealt to Hero (BTN)
MP calls $6, CO folds, <font color="red">Hero raises to $24</font>, 3 folds, MP calls $18

Flop: ($57) 7[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/spade.gif[/img] J[img]/images/graemlins/spade.gif[/img] (2 Players)
MP checks, <font color="red">Hero bets $40</font>, MP calls $40

Turn: ($137) 4[img]/images/graemlins/spade.gif[/img] (2 Players)
MP checks, Hero checks

River: ($137) A[img]/images/graemlins/club.gif[/img] (2 Players)
MP checks, <font color="red">Hero bets $90</font>, <font color="red">MP raises to $566.25 and is All-In</font>