In large bowl, combine all ingredients; mix well. Cover; refrigerate 10 minutes or until slightly firm.
Shape mixture into 4 patties, about 3/4 inch thick.
Spray 12-inch nonstick skillet with nonstick cooking spray. Heat over medium-high heat until hot. Add patties; cook 6 to 8 minutes or until golden brown, turning once. If desired, serve with additional nonfat sour cream.