1Heat 2 cups water to boiling in 2-quart saucepan. Add potatoes and green beans. Heat to boiling; reduce heat. Cover and simmer 9 to 11 minutes or until beans are crisp-tender.
2Meanwhile, mix remaining ingredients in small bowl.
3Drain vegetables; rinse with cold water to cool slightly. Place in serving bowl. Add sour cream mixture; toss to coat. Serve immediately, or refrigerate until serving.