Skip to main content
. 2012 Mar;78(6):2005–2012. doi: 10.1128/AEM.06750-11

Fig 2.

Fig 2

Overexpression of cry19A operon increases yield and stabilizes bipyramidal morphology of Cry19A crystalline inclusions. (A) Schematic illustration of the constructs used to synthesize Cry19A and test the function of the 60-kDa ORF2 protein. In all constructs, synthesis was under the control of the cyt1A-p/STAB-SD sequence. Panel a, pSTAB-19A used to synthesize Cry19A alone; panel b, pSTAB-19Aopn used to synthesize Cry19A and the 60-kDa protein together. Strains that contained or lacked crystals are indicated as (+) or (−), respectively. (B) Phase-contrast micrographs of the recombinant B. thuringiensis 4Q7 strains containing the plasmids illustrated in panel A. Arrows indicate crystals. Panel a, pSTAB-19A used to synthesize Cry19A alone; panel b, pSTAB-19Aopn used to synthesize Cry19A and the 60-kDa protein together. (C) Scanning electron micrographs of purified Cry19A inclusions. Panel a, inclusions produced using the wild-type cry19A operon (pJEG65.5) in B. thuringiensis strain 4Q7; panel b, inclusions produced by expressing the cry19A operon under the control of cyt1A-p/STAB-SD (pSTAB-19Aopn) in the acrystalliferous 4Q7 strain of B. thuringiensis. (D) Analysis of synthesis of Cry19A and the 60-kDa ORF2 protein by different cry19A constructs by the use of SDS-PAGE. Panel a, analysis of proteins synthesized per unit medium. Lane 1, Cry19A produced using the wild-type cry19A operon (pJEG65.5) in B. thuringiensis 4Q7; lane 2, Cry19A produced using the cry19A operon under the control of cyt1A-p/STAB-SD (pSTAB-19Aopn) in B. thuringiensis 4Q7; lane 3, Cry19A produced by cyt1A-p/STAB-SD in B. thuringiensis 4Q7 in the absence of the ORF2 60-kDa protein (pSTAB-19A). All lanes contained equal amounts of sporulated cell lysate. Panel b, analysis of purified Cry19A crystals. After purification, crystals were dissolved in 0.05 M Na2C03 (pH 10.5), and equal amounts of protein were analyzed by SDS-PAGE. Lane M, molecular mass markers; lane 1, Cry19A produced using the wild-type cry19A operon (pJEG65.5) in B. thuringiensis 4Q7; lane 2, Cry19A synthesized using the cry19A operon under the control of cyt1A-p/STAB-SD (pSTAB-19Aopn) in B. thuringiensis 4Q7.