Stolz John F, Basu Partha, Santini Joanne M, Oremland Ronald S
Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, USA.
Annu Rev Microbiol. 2006;60:107-30. doi: 10.1146/annurev.micro.60.080805.142053.
Arsenic and selenium are readily metabolized by prokaryotes, participating in a full range of metabolic functions including assimilation, methylation, detoxification, and anaerobic respiration. Arsenic speciation and mobility is affected by microbes through oxidation/reduction reactions as part of resistance and respiratory processes. A robust arsenic cycle has been demonstrated in diverse environments. Respiratory arsenate reductases, arsenic methyltransferases, and new components in arsenic resistance have been recently described. The requirement for selenium stems primarily from its incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can serve as an electron acceptor in anaerobic respiration, forming distinct nanoparticles of elemental selenium that may be enriched in (76)Se. The biogenesis of selenoproteins has been elucidated, and selenium methyltransferases and a respiratory selenate reductase have also been described. This review highlights recent advances in ecology, biochemistry, and molecular biology and provides a prelude to the impact of genomics studies.
砷和硒很容易被原核生物代谢，参与包括同化、甲基化、解毒和无氧呼吸在内的一系列代谢功能。微生物通过氧化/还原反应影响砷的形态和迁移性，这是抗性和呼吸过程的一部分。在不同环境中已证实存在一个强大的砷循环。最近已描述了呼吸性砷酸盐还原酶、砷甲基转移酶以及砷抗性中的新成分。对硒的需求主要源于其掺入硒代半胱氨酸以及在硒酶中的功能。硒氧阴离子可作为无氧呼吸中的电子受体，形成可能富含（76）Se的元素硒独特纳米颗粒。硒蛋白的生物合成已得到阐明，还描述了硒甲基转移酶和一种呼吸性硒酸盐还原酶。本综述重点介绍了生态学、生物化学和分子生物学方面的最新进展，并为基因组学研究的影响作了铺垫。
