Wiehlmann Lutz, Adams Thorsten, Urbanke Claus, Horatzek Sonja, Jordan Doris, Rosenboom Ilona, Eberl Leo, Tümmler Burkhard
Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.
Department of Biophysical Chemistry, Hannover Medical School, Hannover, Germany.
PLoS Pathog. 2025 Sep 3;21(9):e1013465. doi: 10.1371/journal.ppat.1013465. eCollection 2025 Sep.
Many microorganisms can degrade alkanes, using them as carbon source. The first and key step in alkane utilization is its hydroxylation, which requires a catalytic membrane-bound monooxygenase, a soluble rubredoxin and a soluble rubredoxin reductase. By comparing the phenotype of Pseudomonas aeruginosa strain TBCF10839 with an isogenic mutant that carries a plasposon within the rubredoxin reductase gene rubB (PA5349) and the complemented mutant, we report multiple, yet unknown roles of rubredoxin reductase in the physiology of P. aeruginosa beyond alkane hydroxylation. The plasposon mutant TBCF10839 rubB::Tn5 was severely compromised in its versatility to degrade protein and did not produce any N-acyl homoserine lactone signal molecules. Consequently, the quorum-sensing deficient mutant was avirulent in the Caenorhabditis elegans fast killing infection model. An intact rubB gene was essential for the TBCF10839 strain to inactivate hydrogen peroxide and to persist and multiply in human neutrophils. Upon exposure to hydrogen peroxide, the ternary complex of rubredoxin reductase, rubredoxin and catalase initially mediates the direct reduction to water followed by disproportionation into water and oxygen when the NADH pool is depleted. In summary, P. aeruginosa TBCF10839 engages the electron-transfer proteins rubredoxin reductase and rubredoxin for stress protection and virulence.
许多微生物能够降解烷烃，并将其用作碳源。烷烃利用的第一步也是关键步骤是其羟基化作用，这需要一种催化性膜结合单加氧酶、一种可溶性红素氧还蛋白和一种可溶性红素氧还蛋白还原酶。通过比较铜绿假单胞菌菌株TBCF10839与一个在红素氧还蛋白还原酶基因rubB（PA5349）内携带转座子的同基因突变体以及互补突变体的表型，我们报道了红素氧还蛋白还原酶在铜绿假单胞菌生理学中除烷烃羟基化作用之外的多种未知作用。转座子突变体TBCF10839 rubB::Tn5在降解蛋白质的多样性方面严重受损，并且不产生任何N-酰基高丝氨酸内酯信号分子。因此，群体感应缺陷型突变体在秀丽隐杆线虫快速致死感染模型中无致病性。完整的rubB基因对于TBCF10839菌株灭活过氧化氢以及在人类中性粒细胞中存活和繁殖至关重要。暴露于过氧化氢后，红素氧还蛋白还原酶、红素氧还蛋白和过氧化氢酶的三元复合物最初介导直接还原为水，随后当NADH池耗尽时歧化为水和氧气。总之，铜绿假单胞菌TBCF10839利用电子传递蛋白红素氧还蛋白还原酶和红素氧还蛋白来实现应激保护和致病性。
