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

Abstract

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 caa -type cytochrome c oxidase (caa -Cox) using cytochrome (cyt) c as an electron donor in cells grown with biphenyl versus glucose as the sole carbon source. Homology modeling of KF707 caa -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 - and caa -Cox of Paracoccus and Thermus spp., respectively. To our knowledge, this is the first report demonstrating the presence of a caa -Cox using cyt c as an electron donor in a Pseudomonas species.

Manganese oxidation counteracts the deleterious effect of low temperatures on biofilm formation in Pseudomonas sp. MOB-449

“…In accordance to RT-qPCR assays that indicate a higher expression levels of the genes encoding Cbb3-1 and Cbb3-2 cytochrome c terminal oxidases at 18 °C in the presence of Mn(II), heme peroxidase activity assays results showed a higher abundance of CcoO1 and CcoO2 under these growth conditions. CcoO1 and CcoO2 can be detected in the activity assay since both have a cytochrome c domain (Sandri et al, 2018), that was corroborated for both MOB-449 proteins by the prosite domain scan (https://prosite.expasy. org/) (Hulo et al, 2006).…”

“…RT-qPCR also showed an increment of cox gene expression under this condition. MOB-449 CoxB and CoxM have a predicted cytochrome c domain (https:// prosite.expasy.org/) similar to their bacterial homologs (Sandri et al, 2018). Further, bands with increased staining at 18 °C in the presence of Mn(II) in the TMBZ/SDS-PAGE section corresponding to the MW of these proteins (40-60 kDa) were observed.…”

Complete Genome Sequence of Oxidase-Positive Stenotrophomonas maltophilia Strain SM7059

“…maltophilia SM7059 belongs to sequence type 115 (ST115; MLST 2.0 [http://www.genomicepidemiology.org]). Notably, the genes cc4 and cccA , encoding cytochrome c 4 and cytochrome c 550 , respectively, were annotated in the sequence of SM7059, which indicates the reason that strain SM7059 has a positive result in the oxidase test (9).…”