Venetian 5-10 Deep Set

[TrueBritt]

Effective Stacks: 4600
No read on villain

MP raises to 50
I call in LP with 55
SB calls
BB calls

Flop: ($200) 457r
SB bets 80
BB calls
I raise to 540 with middle set
SB goes all in for andother 4k

Call? Fold?

I'd also like to hear from other deep-stack players as to whether I should smooth-call his initial bet for fear of the straight. Also, would your decision be different if there were 2 of a suit on the flop? What about 3 of a suit?