50NL: Flopped a straight, easy river fold?

[McDirk]

Villain is 28/6/.6 over 125 hands.

50NL
Hero is SB ($26)
Villain is button ($44)

Preflop - folded around to Button
Villain calls BB ($.5)
Hero has (Jh 7d), calls ($.25)
BB checks

Flop (Th 9c 8h)
Hero bets $1.50
BB folds
Villain calls $1.50

Turn (8d)
Hero bets $4.50
Villain calls $4.50

River (Ts)
Hero checks
Villain bets $5.25, Hero ???

This hand just kept getting worse and worse. Is there anything that the villain has here that I beat? The river bet seems pretty small for a bluff from a busted flush draw.