Bardischewsky Frank, Quentmeier Armin, Friedrich Cornelius G
Lehrstuhl für Technische Mikrobiologie, Fachbereich Bio und Chemieingenieurwesen, Universität Dortmund, Dortmund, Germany.
FEMS Microbiol Lett. 2006 May;258(1):121-6. doi: 10.1111/j.1574-6968.2006.00210.x.
Paracoccus pantotrophus strain GBsoxFDelta carries a deletion in the soxF gene that inactivates flavoprotein SoxF-sulfide dehydrogenase. This strain grew with thiosulfate slower than the wild type. GBsoxFDelta cells oxidized thiosulfate at a rate of 40% and hydrogen sulfide at a rate of 45% of the wild type. Complementation of GBsoxFDelta with plasmid pRIsoxF carrying the soxF gene increased these rates to 83% and 70%, respectively. However, GBsoxFDelta and GBsoxFDelta (pRIsoxF) oxidized thiosulfate and hydrogen sulfide to sulfate as evident from the yield of electrons. The thiosulfate oxidation rate of cell-free extracts of strain GBsoxFDelta was increased when supplemented with SoxF isolated from the wild type. However, SoxF did not affect the thiosulfate-oxidizing activity of the Sox enzyme system as reconstituted from the 'as-isolated' four Sox proteins. These data demonstrated that SoxF enhanced chemotrophic thiosulfate oxidation in vivo and acted on some component or condition present in whole cells and cell-free extracts but not present in the reconstituted system.
泛养副球菌GBsoxFDelta菌株的soxF基因存在缺失，该缺失使黄素蛋白SoxF-硫化物脱氢酶失活。该菌株利用硫代硫酸盐生长的速度比野生型慢。GBsoxFDelta细胞氧化硫代硫酸盐的速率为野生型的40%，氧化硫化氢的速率为野生型的45%。用携带soxF基因的质粒pRIsoxF对GBsoxFDelta进行互补，可将这些速率分别提高到83%和70%。然而，从电子产量来看，GBsoxFDelta和GBsoxFDelta（pRIsoxF）都将硫代硫酸盐和硫化氢氧化为硫酸盐。当补充从野生型分离的SoxF时，GBsoxFDelta菌株无细胞提取物的硫代硫酸盐氧化速率增加。然而，SoxF并不影响由“原样分离”的四种Sox蛋白重构的Sox酶系统的硫代硫酸盐氧化活性。这些数据表明，SoxF在体内增强了化能营养型硫代硫酸盐的氧化，并作用于全细胞和无细胞提取物中存在但重构系统中不存在的某些成分或条件。
