Metalloproteins: structure and function-Metal sensing in a bacterial cell: a network that differentiates metals

摘要

Bacterial metal-sensor proteins bind metal ions and repress, derepress or activate the transcription of operons that encode metal-specific efflux pumps, metal transport proteins, metal-sequestering proteins and often the metal-responsive transcriptional regulator itself. In this way the correct concentration of a particular transition metal in the cell is maintained. Emerging evidence suggests that the actions of metal-sensors are interconnected such that the detection of metals in vivo is a shared function of the cell's set of sensors. Determination of relative and absolute metal affinities in vitro is not always sufficient to fully explain which metals each sensor detects inside the cell.