Identification of a third Mn(II) oxidase enzyme in Pseudomonas putida GB-1

Kati Geszvain, Logan Smesrud, Bradley Tebo

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The oxidation of soluble Mn(II) to insoluble Mn(IV) is a widespread bacterial activity found in a diverse array of microbes. In the Mn(II)-oxidizing bacterium Pseudomonas putida GB-1, two Mn(II) oxidase genes, named mnxG and mcoA, were previously identified; each encodes a multicopper oxidase (MCO)-type enzyme. Expression of these two genes is positively regulated by the response regulator MnxR. Preliminary investigation into putative additional regulatory pathways suggested that the flagellar regulators FleN and FleQ also regulate Mn(II) oxidase activity; however, it also revealed the presence of a third, previously uncharacterized Mn(II) oxidase activity in P. putida GB-1. A strain from which both of the Mn(II) oxidase genes and fleQ were deleted exhibited low levels of Mn(II) oxidase activity. The enzyme responsible was genetically and biochemically identified as an animal heme peroxidase (AHP) with domain and sequence similarity to the previously identified Mn(II) oxidase MopA. In the ΔfleQ strain, P. putida GB-1 MopA is overexpressed and secreted from the cell, where it actively oxidizes Mn. Thus, deletion of fleQ unmasked a third Mn(II) oxidase activity in this strain. These results provide an example of an Mn(II)-oxidizing bacterium utilizing both MCO and AHP enzymes.

Original languageEnglish (US)
Pages (from-to)3774-3782
Number of pages9
JournalApplied and Environmental Microbiology
Volume82
Issue number13
DOIs
StatePublished - 2016

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Pseudomonas putida
Oxidoreductases
enzyme
gene
peroxidase
Enzymes
enzymes
bacterium
genes
animal
bacteria
microbial activity
animals
oxidation
Heme
microorganisms
Peroxidase
Bacteria
cells
Genes

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Food Science
  • Biotechnology
  • Ecology

Cite this

Identification of a third Mn(II) oxidase enzyme in Pseudomonas putida GB-1. / Geszvain, Kati; Smesrud, Logan; Tebo, Bradley.

In: Applied and Environmental Microbiology, Vol. 82, No. 13, 2016, p. 3774-3782.

Research output: Contribution to journalArticle

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