Cold-adapted arsenite oxidase from a psychrotolerant Polaromonas species
AuthorsOsborne, Thomas H.
Heath, Matthew D.
Martin, Andrew C.R.
Pankowski, Jaroslaw A.
Hudson-Edwards, Karen A.
Santini, Joanne M.
MetadataShow full item record
AbstractPolaromonas sp. str. GM1 is an aerobic, psychrotolerant, heterotrophic member of the Betaproteobacteria and is the only isolate capable of oxidising arsenite at temperatures below 10 °C. Sequencing of the aio gene cluster in GM1 revealed the presence of the aioB and aioA genes, which encode the arsenite oxidase but the regulatory genes typically found upstream of aioB in other members of the Proteobacteria were absent. The GM1 Aio was purified to homogeneity and was found to be a heterodimer. The enzyme contained Mo and Fe as cofactors and had, using the artificial electron acceptor 2,6-dichlorophenolindophenol, a Km for arsenite of 111.70 ± 0.88 μM and a Vmax of 12.16 ± 0.30 U mg(-1), which is the highest reported specific activity for any known Aio. The temperature-activity profiles of the arsenite oxidases from GM1 and the mesophilic betaproteobacterium Alcaligenes faecalis were compared and showed that the GM1 Aio was more active at low temperatures than that of A. faecalis. A homology model of the GM1 Aio was made using the X-ray crystal structure of the Aio from A. faecalis as the template. Structural changes that account for cold adaptation were identified and it was found that these resulted in increased enzyme flexibility and a reduction in the hydrophobicity of the core.
CitationOsborne TH, Heath MD, Martin ACR, Pankowski JA, Hudson-Edwards KA, Santini JM (2013) 'Cold-adapted arsenite oxidase from a psychrotolerant Polaromonas species', Metallomics, 5 (4), pp.318-324.
PublisherRoyal Society of Chemistry
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as Yellow - can archive pre-print (ie pre-refereeing)
- The respiratory arsenite oxidase: structure and the role of residues surrounding the rieske cluster.
- Authors: Warelow TP, Oke M, Schoepp-Cothenet B, Dahl JU, Bruselat N, Sivalingam GN, Leimkühler S, Thalassinos K, Kappler U, Naismith JH, Santini JM
- Issue date: 2013
- Arsenite oxidation by the heterotroph Hydrogenophaga sp. str. NT-14: the arsenite oxidase and its physiological electron acceptor.
- Authors: vanden Hoven RN, Santini JM
- Issue date: 2004 Jun 7
- Kinetics of arsenite oxidation by Variovorax sp. MM-1 isolated from a soil and identification of arsenite oxidase gene.
- Authors: Bahar MM, Megharaj M, Naidu R
- Issue date: 2013 Nov 15
- Electron transfer through arsenite oxidase: Insights into Rieske interaction with cytochrome c.
- Authors: Watson C, Niks D, Hille R, Vieira M, Schoepp-Cothenet B, Marques AT, Romão MJ, Santos-Silva T, Santini JM
- Issue date: 2017 Oct
- Purification and characterization of arsenite oxidase from Arthrobacter sp.
- Authors: Prasad KS, Subramanian V, Paul J
- Issue date: 2009 Oct