AUTHOR=Arguello Jose, Raimunda Daniel, Padilla-Benavides Teresita TITLE=Mechanisms of copper homeostasis in bacteria JOURNAL=Frontiers in Cellular and Infection Microbiology VOLUME=3 YEAR=2013 URL=https://www.frontiersin.org/articles/10.3389/fcimb.2013.00073 DOI=10.3389/fcimb.2013.00073 ISSN=2235-2988 ABSTRACT=Copper is an important micronutrient required as a redox co-factor in the catalytic centers of enzymes. However, free copper is a potential hazard because of its high chemical reactivity. Consequently, organisms exert a tight control on Cu+ transport (entry-exit) and traffic through different compartments, ensuring the homeostasis required for cuproprotein synthesis and prevention of toxic effects. Recent studies based on biochemical, bioinformatics, and metalloproteomics approaches, reveal a highly regulated system of transcriptional regulators, soluble chaperones, membrane transporters, and target cuproproteins distributed in the various bacterial compartments. As a result, new questions have emerged regarding the diversity and apparent redundancies of these components, their irregular presence in different organisms, functional interactions, and resulting system architectures.