Eurobic9, 2-6 September, 2008, Wrocław, Poland
Roland K. O. Sigel (University of Zürich, Switzerland) -
EUROBIC Medal 2008
The EUROBIC Award was created when the EUROBIC conferences were established and soon settled a new
tradition to honor promising young, and other bioinorganic chemists deserving an honor of high calibre. The first
medallist was Fred Hagen (1994; now professor at Delft, NL), and since then every 2 years a medal was granted,
after a basic endowment had been constituted. The subsequent medallists are Claudio Luchinat (1996), Fraser
Armstrong (1998), Simon P. J. Albracht and Juan C. Fontecilla-Camps (2000), Peter M. H. Kroneck (2002),
Maria Armenia Carrondo (2004), as well as Antonio Xavier (2006).
When looking at these names of previous EUROBIC medallists in Bioinorganic Chemistry, two things become
evident: Virtually exclusively they have come from the "Bio" side (or from physical biochemistry), and without
exception their research was centered around metal-protein chemistry, be it mechanistic, structural, or
spectroscopic. This year for the first time the EUROBIC medal is awarded to a young scientist who represents
the second part in the definition of our discipline of "bioinorganic chemistry", namely "Inorganic"; i.e. the 2008
winner is an inorganic coordination chemist by training. Moreover, and again it is a change compared to
previous years, the expertise and research interests of this year's medallist are in the area of metal-nucleic acid
interactions rather than that of the field of metalloproteins.
Roland K. O. Sigel, working at the University of Zurich, Switzerland, receives the EUROBIC medal 2008 in
recognition of his contributions to further the basic understanding of metal ion interactions with nucleic acids.
Born in 1971 in Basel, Switzerland, Roland Sigel received his chemistry education at the University of Basel
(Diploma) and at the University of Dortmund (Ph.D. degree in 1999). Following a postdoctoral stay at Columbia
University, New York City, working with Anna Marie Pyle, he became Oberassistent at the Department of
Chemistry and Biochemistry at the University of Zurich in 2003 and was after a short time promoted to Assistant
Professor, endowed with a SNF-Förderungsprofessur of the Swiss National Science Foundation.
As a Ph.D. student in the group of Bernhard Lippert (Dortmund), Roland Sigel has been studying interactions
between model nucleobases and metal species, mainly of platinum, in an attempt to elucidate the influence of the
metal on the basic characteristics of the nucleobases, such as acid-base properties and internucleobase hydrogen
bond formation. As a result, several fundamental aspects of unexpected base pairing schemes between metal-
carrying nucleobases were unravelled, including experimental evidence on the role of a coordinated metal on the
strength of a Watson-Crick base pair. During his postdoctoral stay at Columbia University he moved deeply into
the field of large RNAs and specifically that of the catalytically active ribozymes. Ever since his return to
Switzerland (in 2003) Roland Sigel has been developing his independent research on the coordination chemistry
of large nucleic acids, i.e. mainly RNAs, but also DNAs. A major focus of this recent work is thereby the role of
metal ions on the folding and on the catalysis of group II intron ribozymes.
As an inorganic chemist he tries to answer very fundamental questions, such as those of selectivity and
specificity of metal binding and their effects on structure and function. 3-D NMR structures of important RNA
domains are now routinely performed in the Sigel lab with the goal of finding the exact positioning of the
nucleotides that are crucial for catalysis and, of course, of identifying the metal ions close by and their
coordination behaviour. For a number of metal ions intrinsic affinities for particular domains of the group 2
intron have been derived from 2D-NMR experiments by use of an iterative procedure developed in his group in
Zürich. It is surprising to see how different metal ions interfere with each other and with the RNA, even at very
low concentrations of the "wrong" metal ion! To understand in detail the role of metal ions on the consecutive
steps of folding of large RNA domains is no doubt a major challenge in his future work. Most recent results on
single group II intron molecules have thereby revealed a new paradigm in RNA folding.
Finally, one major focus during the last few years has been the study of metal ion binding properties of small
mono- and dinucleotides in an attempt to compare these findings with our current knowledge on metal binding to
larger nucleic acids and to extrapolate this information, respectively. Last but not least, other areas of his
research, often in international collaborations, include projects on a B12-dependent riboswitch of E. coli as well
as on metal chains in the interior of nucleic acid duplexes.
Jan Reedijk, Leiden, the Netherlands