US EPA

1070405 

Journal Article 

Review 

Linking selenium biogeochemistry to the sulfur-dependent biological detoxification of arsenic 

Couture, R-M; Sekowska, A; Fang, G; Danchin, A 

2012 

Yes 

Environmental Microbiology
ISSN: 1462-2912
EISSN: 1462-2920 

14 

7 

1612-1623 

English 

22515279 

10.1111/j.1462-2920.2012.02758.x 

WOS:000305904500002 

Geochemistry often reveals unexpected (anti)correlations. Arsenic (As) and selenium (Se) are cases in point. We explore the hypothesis that bacteria living in an As-replete environment recruited a biological process involving Se and sulfur to fulfil their need for As detoxification. In analogy with the formation of arsenolipids and arsenosugars, which are common non-toxic As metabolites derived from microbial and plant metabolism, we attempt to explain the prevalence of novel sulfur-containing As derivatives, in particular monothioarsenate, in the aqueous environment. Thiolated-As species have been overlooked so far mainly because of the difficulty of their identification. Based on comparative genomics, we propose a scenario where SelD and SelU proteins, commonly used to make selenophosphate and modify transfer RNA, have been recruited to make monothioarsenate, a relatively innocuous arsenical. This hypothesis is discussed in terms of the relative geochemical distribution of Se and As.