Comprehensive insights into arsenic- and iron-redox genes, their taxonomy and associated environmental drivers deciphered by a meta-analysis

•ccoN likely enhances host survival in Fe-limiting environments.•iro and ccoN may be associated with As(V) detoxification in mesophilic environments.•Cytochromes with putative roles in Fe-redox correlate with As(V) reduction genes.•Taxonomic analysis showed unprecedented diversity, especially for arsC and petC.•arsC, petC and ccoN predominate and likely play key roles in As and Fe global cycling.