Research: RNase structure

20 October 2005

The structure of a bacterial RNA-processing enzyme provides clues to its mechanisms of action.

RNA has many vital roles in the cell. Messenger RNA (mRNA), for example, is a key intermediary between DNA and protein. Not surprisingly, then, production of RNA is finely regulated – and so too is its destruction.

In the bacterium E. coli, the enzyme RNase E plays a key role in mRNA stability, destroying unwanted RNA molecules and trimming others in carefully controlled ways. The structure of this enzyme, produced by Wellcome Trust Senior Research Fellow Dr Ben Luisi and colleagues at the University of Cambridge, suggests ways in which it operates.

The active protein is built from four interwoven subunits, and its active site is surprisingly similar to a DNA-processing enzyme, suggesting they may have a common evolutionary origin. Interestingly, the part of the enzyme recognising the mRNA (at one of its ends) is some way away from the active site, suggesting that the enzyme may act as a hinged molecular 'mousetrap' when an RNA target molecule has been snared.

External links

• Callaghan AJ et al. Structure of Escherichia coli RNase E catalytic domain and implications for RNA turnover. Nature 2005;437(7062):1187–91.