[1] UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720
[2] LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720
[3] LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720
[4] UNIV CALIF BERKELEY,DEPT BIOPHYS,BERKELEY,CA 94720
[5] UNIV PACIFIC,SCH DENT,DEPT BIOCHEM,SAN FRANCISCO,CA 94115