Pseudomonas pseudoalcaligenes KF707 grown with biphenyl expresses a cytochrome caa3 oxidase that uses cytochrome c4 as electron donor

摘要

Combining peroxidase activity‐based heme staining (TMBZ/SDS/PAGE) with mass spectrometry analyses (Nano LC‐MS/MS) of protein extracts from wild‐type and appropriate mutants, we provide evidence that the polychlorinated biphenyl degrader Pseudomonas pseudoalcaligenes KF707 primarily expresses a caa3‐type cytochrome c oxidase (caa3‐Cox) using cytochrome (cyt) c4 as an electron donor in cells grown with biphenyl versus glucose as the sole carbon source. Homology modeling of KF707 caa3‐Cox using the three‐dimensional structure of that from Thermus thermophilus highlights multiple similarities and differences between the proton channels in subunit I of the aa3‐ and caa3‐Cox of Paracoccus and Thermus spp., respectively. To our knowledge, this is the first report demonstrating the presence of a caa3‐Cox using cyt c4 as an electron donor in a Pseudomonas species.