So this guy is a tight fish running 11/7/1.8 with 1.7% 3bet. He plays 4-6 tables, and I've never seen him do this before. Turn call? Bet river? Sizing?

PokerStars No-Limit Hold'em, $2.00 BB (8 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

saw flop

MP1 ($200)
MP2 ($325.75)
Hero (CO) ($250)
Button ($116.75)
SB ($200)
BB ($159.95)
UTG ($139)
UTG+1 ($158.25)

Preflop: Hero is CO with A, A
4 folds, Hero bets $6, 1 fold, SB calls $5, BB calls $4

Flop: ($18) 5, K, Q (3 players)
SB bets $12, BB calls $12, Hero calls $12

Turn: ($54) Q (3 players)
SB bets $38, 1 fold, Hero calls $38

River: ($130) 3 (2 players)
SB checks, Hero bets $56