NO Production by Pseudomonas aeruginosa cd1 Nitrite Reductase

Abstract

SummaryThe structural and catalytic properties of Pseudomonas aeruginosa cd 1 nitrite reductase, a key enzyme in bacterial denitrification, are reviewed in this paper. The mechanism of reduction of nitrite to NO is discussed in detail with special attention to the structural interpretation of function. The ability to stabilize negatively charged molecules, such as the substrate (nitrite) and other ligands (hydroxide and cyanide), is a key feature of catalysis in cd 1 NIRs. The positive potential in the active site is largely due to the presence of the two conserved distal histidines, which are involved in both substrate binding and product release. IUBMB Life, 55: 617-621, 2003

Decaying Cyanobacteria decrease N2O emissions related to diversity of intestinal denitrifiers of Chironomus plumosus

“…This result was consistent with a previous report (Poulsen et al, 2014). The genera Pseudomonas and Stenotrophomonas belonging to Gamma-proteobacteria were ubiquitous in sediment and waste plants, while not detected in the gut due to primer partial (Cutruzzola et al, 2003;Bartacek et al, 2010;Bellini et al, 2013;Desloover et al, 2014;Zheng et al, 2014). The community composition of nitrite-and nitrous-oxide-reducing bacteria in the gut was indeed affected by the presence of cyanobacteria.…”

Maturation of the cytochrome cd1 nitrite reductase NirS from Pseudomonas aeruginosa requires transient interactions between the three proteins NirS, NirN and NirF

“…In P. aeruginosa , the second step of denitrification is catalysed by the periplasmic cytochrome cd 1 nitrite reductase NirS [2]. In addition to its important function during denitrification, NirS also seems to contribute to the virulence of P. aeruginosa by producing the signal molecule NO [3].…”

Y25S Variant of Paracoccus pantotrophus Cytochrome cd1 Provides Insight into Anion Binding by d1 Heme and a Rare Example of a Critical Difference between Solution and Crystal Structures

“…These observations show that the d 1 heme, compared with protoheme, is tailored to bind anions in a ferrous rather than a ferric state. The covalent modifications distinguishing d 1 heme from "normal" heme are electronegative alterations, increasing the positive potential of the d 1 heme iron (34). The immediate environment of the d 1 heme active site also contains two highly conserved histidine residues (His 345 and His 388 in P. pantotrophus), which, if protonated, contribute to the positive electrostatic potential of the active site (8).…”