Differential Expression Protein Between The Thuringiensin-yield Bacillus Thuringiensis Strain CT-43 And Its Mutants

Thuringiensin is a non-specific heat-stable insecticidal toxin produced by some Bacillus thuringiensis strains. This exotoxin is heat-stable and its chemical structure is similar to that of nucleotides, its melecular weight is 701. The mechanism of insecticidal action is to inhibit the production of DNA-dependent RNA polymerase by competition with ATP, so it has a broad-spectrum of effectivity against many pests. The toxicity of thuringiensin is much less than that of most chemical insecticides; therefore it shows great potential to become a very useful insecticide for a wide range of pests.In order to clarify the influential role factor of biosynthesis and metabolic of thuringiensin production, differential expression analysis between the high thuringiensin-yield Bacillus thuringiensis strain CT-43 and its mutants, high production strain CT-43-1C and non-production strain F-15, is conducted based on the 2-D gel. Then through mass spectrum (MS) identification and bio-informatics to analyze the detected proteins. Thirteen spots were selected to be detected by the mass spectrum, and nine of them were successfully identified finally. Among which, six proteins including in the basal metabolism pathway are possibly deduced that associate with the synthesis of thuringiensin production. The deletion of dihydroxyacetone kinase and N-acetylglucosamine-6-phosphate deacetylase, or the improvement of Aconitate hydratase 1 may affect the metabolism pathway of Thuringiensin. And one necessary protein UvrB/UvrC belonging to the secretion pathway was speculated to be related to the thuringiensin production and secretion way, and one protein named phoH protein was deleted in the mutant strain, which was deduced to be related to the thuringiensin production synthesis's metabolism substrate as well as the energy metabolism; leucyl-tRNA synthetase reduced, which probably caused that Bacillus thuringiensis strain F-15 did not produce thuringiensin. In this research , There are six protein found to be connected with the influential role protein of biosynthesis and metabolic of thuringiensin production by comparative proteomics. And this research provides a supporting evidence of thuringiensis gene cluster cloning and biosynthetic analysis.