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Citation
Tags
HERO ID
1337503
Reference Type
Journal Article
Title
Cold-adapted arsenite oxidase from a psychrotolerant Polaromonas species
Author(s)
Osborne, TH; Heath, MD; Martin, AC; Pankowski, JA; Hudson-Edwards, KA; Santini, JM
Year
2013
Is Peer Reviewed?
1
Journal
Metallomics
ISSN:
1756-5901
EISSN:
1756-591X
Volume
5
Issue
4
Page Numbers
318-324
Language
English
PMID
23150098
DOI
10.1039/c2mt20180a
Web of Science Id
WOS:000316956400005
Abstract
Polaromonas 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 K(m) for arsenite of 111.70 ± 0.88 μM and a V(max) 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.
Tags
IRIS
•
Arsenic Hazard ID
1. Initial Lit Search
PubMed
WOS
PubMed
Considered New
WOS
Considered New
2. Lit Search Updates through Oct 2015
PubMed
WOS
Considered
4. Considered through Oct 2015
6. Cluster Filter through Oct 2015
7. Other Studies through Oct 2015
Other
•
Arsenic (Inorganic)
1. Literature
PubMed
Lit search updates through Oct 2015
3. Hazard ID Screening
Other potentially supporting studies
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