In
molecular biology, the ferric uptake regulator family is a family of
bacterialproteins involved in regulating
metal ion uptake and in metal
homeostasis. The family is named for its founding member, known as the ferric uptake regulator or ferric uptake regulatory protein (Fur). Fur proteins are responsible for controlling the
intracellularconcentration of
iron in many
bacteria. Iron is essential for most organisms, but its concentration must be carefully managed over a wide range of environmental conditions; high concentrations can be
toxic due to the formation of
reactive oxygen species.[1]
Function
Members of the ferric uptake regulator family are
transcription factors that primarily exert their regulatory effects as
repressors: when bound to their cognate metal ion, they are capable of binding
DNA and preventing
expression of the genes they regulate, but under low concentrations of metal, they undergo a
conformational change that prevents DNA binding and lifts the repression.[2][3] In the case of the ferric uptake regulator protein itself, its immediate downstream target is a
noncoding RNA called
RyhB.[2]
In addition to the ferric uptake regulator protein, members of the Fur family are also involved in maintaining homeostasis with respect to other ions:[4]
Metal homeostasis can be a factor in bacterial
virulence, an observation with a particularly long history in the case of iron.[15][16][17] In some cases, expression of
virulence factors is under the regulatory control of the Fur protein.[1][2]
^Bullen JJ, Rogers HJ, Griffiths E (1978). "Role of Iron in Bacterial Infection". Modern Aspects of Electrochemistry. Current Topics in Microbiology and Immunology. Vol. 80. pp. 1–35.
doi:
10.1007/978-3-642-66956-9_1.
ISBN978-1-4612-9003-2.
PMID352628.