title: Mislocalization of Rieske protein PetA predominantly accounts for the aerobic growth defect of Tat mutants in Shewanella oneidensis.
abstract: Shewanella oneidensis exhibits a remarkable versatility in respiration, which largely relies on its various respiratory pathways. Most of these pathways are composed of secretory terminal reductases and multiple associated electron transport proteins that contain cofactors such as Fe-S, molybdopterin, and NiFe. The majority of these cofactors are inserted enzymatically in the cytoplasm, and thus are substrates of the twin-arginine translocation (Tat) protein export system, which transports fully folded proteins. Using genomic array footprinting, we discovered that loss of TatA or TatC caused a reduction in the growth rate of S. oneidensis under aerobic conditions. Mutational analysis of the predicted Tat substrates revealed that PetA, the Rieske Fe-S subunit of the ubiquinol-cytochrome c reductase, predominantly dictates the aerobic growth defect of tat mutants in S. oneidensis. In addition, evidence is presented that the signal sequence in PetA appears to be resistant to cleavage after the protein is inserted into the cytoplasmic membrane.
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Qixia
authors.initials: Q
authors.lastname: Luo
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Dong
authors.forename: Haijiang
authors.initials: H
authors.lastname: Chen
authors.forename: Haichun
authors.initials: H
authors.lastname: Gao
mesh_terms: D058947:Bacterial Secretion Systems / Q000235:genetics*; D015153:Blotting, Western; D019295:Computational Biology; D014450:Electron Transport Complex III / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005453:Fluorescence; D040461:Gene Components; D026901:Membrane Transport Proteins / Q000235:genetics*; D018613:Microscopy, Confocal; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D010101:Oxygen Consumption / Q000502:physiology; D020592:Shewanella / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D013045:Species Specificity
chemical_list: D058947:Bacterial Secretion Systems; D026901:Membrane Transport Proteins; C037989:Rieske iron-sulfur protein; D014450:Electron Transport Complex III