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Volume 2010, Article ID 106341, 6 pages
Research Article

Extensive Lysine Methylation in Hyperthermophilic Crenarchaea: Potential Implications for Protein Stability and Recombinant Enzymes

1Centre for Biomolecular Sciences, University of St Andrews, Fife KY16 9ST, UK
2Departamento de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avenida. Diagonal 645, 08028 Barcelona, Spain

Received 20 May 2010; Accepted 1 July 2010

Academic Editor: Julie Maupin-Furlow

Copyright © 2010 Catherine H. Botting et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In eukarya and bacteria, lysine methylation is relatively rare and is catalysed by sequence-specific lysine methyltransferases that typically have only a single-protein target. Using RNA polymerase purified from the thermophilic crenarchaeum Sulfolobus solfataricus, we identified 21 methyllysines distributed across 9 subunits of the enzyme. The modified lysines were predominantly in -helices and showed no conserved sequence context. A limited survey of the Thermoproteus tenax proteome revealed widespread modification with 52 methyllysines in 30 different proteins. These observations suggest the presence of an unusual lysine methyltransferase with relaxed specificity in the crenarchaea. Since lysine methylation is known to enhance protein thermostability, this may be an adaptation to a thermophilic lifestyle. The implications of this modification for studies and applications of recombinant crenarchaeal enzymes are discussed.