Differential enhancement of Cry2A versus Cry11A yields in Bacillus thuringiensis by use of the cry3A STAB mRNA sequence

Previously we demonstrated that the yield of Cry3A (70 kDa) can be increase d as much as 10-fold when cry3A including its upstream STAB-SD mRNA stabili zing sequence is expressed in Bacillus thuringiensis under the control of c yt1A promoters. To determine whether the cyt1A promoters/STAB-SD combinatio n (cyt1AP/STAB) has broader applicability, we used it to synthesize two oth er Cry endotoxins in the 70-kDa mass range, Cry2A and Cry11A. Combination o f cyt1AP/STAB with orfs 2 and 3 of the cry2A operon yielded about 4.4-fold the amount of Cry2A obtained with the wild-type cry2A operon. The yield of Cry11A obtained with a construct that contained the cyt1AP/STAB, cry11A and the 20-kDa protein gene was 1.3-fold the amount obtained with a construct similar to the wild-type operon. These results demonstrate that the cyt1AP/ STAB combination can enhance synthesis of different Cry proteins significan tly, but that the level of enhancement varies with the specific protein syn thesized. (C) 1999 Published by Elsevier Science B.V. All rights reserved.