[1] UNIV CONNECTICUT, DEPT MOLEC & CELL BIOL, STORRS, CT 06269 USA
[2] POHANG UNIV SCI & TECHNOL, DEPT LIFE SCI, POHANG 790600, SOUTH KOREA
[3] PENN STATE UNIV, DEPT BIOL, UNIVERSITY PK, PA 16802 USA
[4] KOREA ADV INST SCI & TECHNOL, DEPT LIFE SCI, TAEJON 305701, SOUTH KOREA