[1] UNIV ALBERTA, MRC, PROT STRUCT & FUNCT GRP, EDMONTON T6G 2H7, ALBERTA, CANADA
[2] UNIV ALBERTA, DEPT BIOCHEM, EDMONTON T6G 2H7, ALBERTA, CANADA
[3] PURDUE UNIV, SCH VET MED, DEPT ANAT, W LAFAYETTE, IN 47907 USA
[4] UNIV MASSACHUSETTS, MED CTR, DEPT BIOCHEM, WORCESTER, MA 02160 USA