the purified MBP (Fig. 4A, lane 2). The fusion protein
specifically reacted with calreticulin antibody in Western blot
analysis (Fig. 4B, lane 1). Enzymatic cleavage of the Cal-
MBP with factor Xa released a 60-kDa protein reacting with
calreticulin antiserum (Fig. 4B, lane 2). Upon incubation of
purified Cal-MBP with RV 3' (+)-SL RNA, no measurable
RNA binding was observed.