Pseudomonas pseudoalcaligenes Pseudomonas pseudoalcaligenes KF KF 707 grown with biphenyl expresses a cytochrome caa caa 3 3 oxidase that uses cytochrome c c 4 4 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 KF 707 primarily expresses a caa 3 ‐type cytochrome c oxidase ( caa 3 ‐Cox) using cytochrome (cyt) c 4 as an electron donor in cells grown with biphenyl versus glucose as the sole carbon source. Homology modeling of KF 707 caa 3 ‐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 aa 3 ‐ and caa 3 ‐Cox of Paracoccus and Thermus spp., respectively. To our knowledge, this is the first report demonstrating the presence of a caa 3 ‐Cox using cyt c 4 as an electron donor in a Pseudomonas species.