Iron-sulfur cluster-based sensors
Jeffrey Green, Jason C. Crack, Adrian J. Jervis, David P. Dibden, Laura J. Smith, Andrew J. Thomson and Nick E. Le Brun
from: Sensory Mechanisms in Bacteria: Molecular Aspects of Signal Recognition (Edited by: Stephen Spiro and Ray Dixon). Caister Academic Press, U.K. (2010)
Iron-sulfur clusters are an ancient and important class of co-factor inherited from early anaerobic life forms. The most commonly encountered type of iron-sulfur cluster have between two and four iron atoms coordinated to the polypeptide backbone and bridged by inorganic sulfide. They are highly stable in anaerobic solution, even self-assemblying in vitro if an appropriate scaffold is provided, but inherently unstable in aerobic solutions. The in vivo assembly of iron-sulfur clusters is closely regulated and requires dedicated enzymes encoded by the suf, isc or nif operons, with the majority of living organisms having retained iron-sulfur clusters as catalysts, electron transfer agents, structural elements, or, more intriguingly, as sensors. In this chapter, we briefly summarise iron-sulfur cluster biogenesis before discussing specific examples of iron-sulfur cluster sensory proteins in which the status of the iron-sulfur cluster represents a key decision point within a regulatory network in response to important environmental cues read more ...