Identification of cry-type genes on 20-kb DNA associated with Cry1 crystal proteins from Bacillus thuringiensis.
Heterologous DNA fragments (20-kb) associated with Cry1 crystal proteins (protoxins) from a soil-isolated Bacillus thuringiensis strain 4.0718 were isolated and analyzed. RFLP patterns of the PCR products showed that the 20-kb DNA fragments harbored cry1Aa, cry1Ac, cry2Aa, and cry2Ab genes. Furthermore, a 4.2-kb DNA fragment, which contained the promoter, the coding region, and the terminator of cry1Ac gene, was cloned from the 20-kb DNAs by PCR, and then the cry1Ac gene was expressed in an acrystalliferous B. thuringiensis strain 4Q7 by using E. coli-B. thuringiensis shuttle vector pHT3101. SDS-PAGE and microscopy studies revealed that the recombinant could express 130-kDa Cry1Ac protoxin and produce bipyramidal crystals during sporulation. Bioassay results proved that crystal-spore mixture from the recombinant was toxic to Plutella xylostella. This was the first report of cry-type genes present on 20-kb DNA associated with Cry1 protoxins of B. thuringiensis.
Xia
Liqiu
L
College of Life Science, Hunan Normal University, Changsha, 410081, PR, China. xialq@hunnu.edu.cn
Sun
Yunjun
Y
Ding
Xuezhi
X
Fu
Zujiao
Z
Mo
Xiangtao
X
Zhang
He
H
Yuan
Zhiming
Z
D001413:Bacillus thuringiensis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D001427:Bacterial Toxins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D004269:DNA, Bacterial / Q000032:analysis* / Q000235:genetics; D004731:Endotoxins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D005798:Genes, Bacterial; D006460:Hemolysin Proteins
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis