Synergistic function of ars genes in arsenic detoxification and biosynthesis of organoarsenicals

Arsenic contamination poses a major threat to ecosystems and human health. Microorganisms have developed diverse resistance mechanisms to manage arsenic toxicity, primarily through the function of arsenic resistance (ars) operons. These gene clusters, often located close together in the genome, operate synergistically to regulate and enhance arsenic resistance. The ars genes encode proteins involved in arsenic transcriptional regulation, transport, reduction, and methylation, leading to arsenic detoxification and also the formation of complex compounds such as arsenosugars and arsinothricin ((2-amino-4-(hydroxymethylarsinoyl)butanoate, AST). Cooperative ars gene interactions have been involved in coordinated expression and regulation, working together to improve the organism's capacity to decrease arsenic toxicity, resulting in more effective detoxification processes. Within ars operons, in addition to individual single-function genes, there are also fusion genes, which are genetic sequences formed from the merging of two distinct ars genes. These fusions provide microorganisms with novel capabilities that enhance their adaptability and survival under arsenic exposure. This review explores the diversity and organization of ars operons across microbial species, emphasizing the cooperative interactions between ars genes, including fusion genes, and their role in the synthesis of complex arsenic compounds. These processes illustrate the evolutionary adaptation and ecological significance of the mechanisms of arsenic biotransformations. Understanding these synergistic interactions not only highlights microbial survival strategies but also offers insights into potential applications for arsenic-based antibiotics development and environmental management.