MIX juice, dressing and tarragon in shallow baking dish with whisk until well blended. Add fish; turn to evenly coat both sides of each fillet. Refrigerate 1 hour to marinate.
HEAT oven to 450ºF. Remove fish from marinade; pour marinade into small saucepan. Return fish to baking dish.
BAKE fish 15 min. or until fish flakes easily with fork. Meanwhile, bring water to boil in medium saucepan. Add rice, beans, salt and pepper; cover. Cook on low heat 5 min.; stir. Remove from heat; let stand 5 min.
MEANWHILE, bring marinade to boil; simmer on low heat 5 min. Add sour cream; cook until heated through, stirring occasionally with whisk. Serve over fish and green bean pilaf.