Protein genes from Thiobacillus ferrooxidans that change their expression by growth under different energy sources

摘要

We developed a protocol to obtain three different fractions from Thiobacillus ferrooxidans: soluble proteins (SP), inner membrane proteins (IMP) and outer membrane proteins (OMP). SDS-PAGE protein pattern comparisons of each of these fractions from T. ferrooxidans cells grown in iron or sulfur allowed us to connect the expression of some polypeptides with the energy source. We employed 2D-PAGE to isolate the individual polypeptides IMP30 and OMP40. To identify each protein, we determined the NH_2-terminal end sequences of the complete polypeptides and of some of the corresponding internal peptides. With these results, we obtained part of the coding region of the omp40 gene by DOP-PCR and we began the identification of the p30 gene by SSP-PCR. The Omp40 sequence obtained so far presented no similarities to other known outer membrane proteins. The partial sequence of the P30 protein showed a high level of similiraty to proteins CbbQ, NorQ and NirQ.