David Giedroc Seminar
November 28 @ 1:30 PM - 2:30 PM - Lilly Room 1-117
Transition Metal Homeostasis in Bacterial Pathogens: Structure and Mechanism
All prokaryotes encode a panel of metal sensor or metalloregulatory proteins that govern the expression of genes that allows an organism to quickly adapt to toxicity or deprivation of both biologically essential transition metalions, e.g., Zn, Cu, Fe, and heavy metal pollutants. As such, metal sensor proteins can be considered arbiters of intracellular transition metal bioavailability and thus potentially control the metallation state of the metalloproteins in the cell. Metal sensor proteins are specialized allosteric proteins that regulate transcription as a result direct binding of one or two cognate metal ions, to the exclusion of all others. In most cases, the binding of the cognate metal ion induces a structural change in a protein oligomer that either activates or inhibits operator DNA binding. A quantitative measure of the degree to which a particular metal drives metalloregulation of operator DNA-binding is the allosteric coupling free energy, ΔGc. Structural, thermodynamic and cell biological approaches will be discussed with a focus on zinc homeostasis and copper resistance in the Gram-positive respiratory pathogen, Streptococcus pneumoniae.
- Rebecca Harding