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Published online: 18 April 2007 | doi:10.1038/nchina.2007.49

Bacterial evolution: Good housekeeping

Tim Reid

Introduction

An ancient bacterium found in underwater volcanoes and hot springs explains the evolution of gene-transfer processes in cells, according to a study led by researchers from the Graduate School of the Chinese Academy of Sciences in Shanghai. The bacterium Aquifex aeolicus, which prefers to grow at temperatures around 90 °C, contains a unique enzyme that destroys unnecessary material and is essential for cell survival.

The enzyme, -LeuRS, belongs to a group known as synthetases that select amino acids from the cellular pool and transfer them to RNA. Synthetases sometimes activate the wrong amino acids, causing RNA to carry false genetic information. Enduo Wang and co-workers¹ identified the part of the -LeuRS molecule in A. aeolicus that destroys these misactivated amino acids and RNA in a process known as editing. They also transplanted the crucial synthetase section into an E. coli bacterium, and observed editing in the cell.

A. aeolicus, the oldest of four bacteria species studied, showed the greatest editing activity. In newer species, the synthetase molecules have evolved greater efficiency and specialization alongside the evolution of RNA. In these species the authors suggested that it is less probable that the false RNA will be created in the first place, making the editing process obsolete.

The authors in this work are from:
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China; UPR9002, IBMC du CNRS and Université Louis Pasteur, Strasbourg, France.

References

1. Zhao, M. W. et al. Leucyl-tRNA synthetase from the ancestral bacterium Aquifex aeolicus contains relics of synthetase evolution. EMBO J. 24, 1430–1439 (2005).  | Article |