The advent of heme during evolution allowed organisms possessing this compound to
safely and efficiently carry out a variety of chemical reactions that otherwise were difficult or …

The ferric uptake regulator (Fur) protein, as originally described in Escherichia coli, is an iron-
sensing repressor that controls the expression of genes for siderophore biosynthesis and …

Heme (iron protoporphyrin IX) is an essential molecule for numerous living organisms. Not
only does it serve as a prosthetic group in enzymes, it also acts as a signaling molecule that …

Macrophages exert prominent effects in the defense of the respiratory tract from airborne
pathogens. These cells are specialized to recognize, phagocytose, and destroy these …

Exposure to hydrogen peroxide (H2O2) and other reactive oxygen species is a universal
feature of life in an aerobic environment. Bacteria express enzymes to detoxify H2O2 and to …

The conjugation of arginine, by arginyl-transferase, to N-terminal aspartate, glutamate or
oxidized cysteine is a part of the N-end rule pathway of protein degradation. We report that …

The alpha-proteobacteria include several important genera, including the symbiotic N 2-
fixing “rhizobia” the plant pathogen Agrobacterium, the mammalian pathogens Brucella …

Iron is critical for bacterial growth, but problems arise from the toxicity of excess iron; thus,
iron uptake is subject to tight control. The most widely found and best-studied iron …

Iron is an essential nutrient, but it can also be toxic. Therefore, iron homeostasis must be
strictly regulated. Transcriptional control of iron-dependent gene expression in the rhizobia …

Bioleaching acidophiles inhabit environments with unusually high concentrations of iron that
can potentially cause oxidative stress via the Fenton reaction in which dangerous reactive …