Wu D, Federici B A
Department of Entomology, University of California, Riverside 92521.
Appl Microbiol Biotechnol. 1995 Jan;42(5):697-702. doi: 10.1007/BF00171947.
Previous studies have shown that a 20-kDa protein enhances production of the insecticidal CytA and CryIVA proteins of Bacillus thuringiensis in Escherichia coli as well as CytA production and crystal formation in B. thuringiensis. To determine whether the 20-kDa protein could enhance CryIVD production, an expression vector was constructed with the 20-kDa open-reading frame under control of cryIA(c) promoters and the cryIVD gene under control of its own promoter. Acrystalliferous cells of B. thuringiensis transformed with this plasmid, designated pWF53, produced large bitrapezoidal CryIVD crystals that averaged 1.3 x 0.92 x 0.31 microns, approximately fivefold larger in volume than wild-type CryIVD crystals, and 1.7 fold the volume of crystals produced using the cryIVD operon, which contains the cryIVD gene and the gene for the 20-kDa protein. These results demonstrate that the 20-kDa protein significantly improves net synthesis of CryIVD and promotes CryIVD crystal formation. Improved production of proteins as diverse as CryIVD and CytA by the 20-kDa protein indicates this protein may be useful in facilitating the production of other proteins.
先前的研究表明，一种20 kDa的蛋白质可提高苏云金芽孢杆菌的杀虫CytA和CryIVA蛋白在大肠杆菌中的产量，以及苏云金芽孢杆菌中CytA的产量和晶体形成。为了确定20 kDa的蛋白质是否能提高CryIVD的产量，构建了一个表达载体，其中20 kDa的开放阅读框受cryIA(c)启动子控制，cryIVD基因受其自身启动子控制。用该质粒（命名为pWF53）转化的苏云金芽孢杆菌无晶体细胞产生了大的双梯形CryIVD晶体，平均尺寸为1.3×0.92×0.31微米，体积约为野生型CryIVD晶体的五倍，是使用包含cryIVD基因和20 kDa蛋白质基因的cryIVD操纵子产生的晶体体积的1.7倍。这些结果表明，20 kDa的蛋白质显著提高了CryIVD的净合成并促进了CryIVD晶体的形成。20 kDa的蛋白质提高了CryIVD和CytA等多种蛋白质的产量，表明该蛋白质可能有助于其他蛋白质的生产。
