Section Days abstract book 2010.indd - RUB Research School ...

LS_3
TWO EXTRAORDINARY BACTERIAL
RNA THERMOMETERS
Annika M. Cimdins and Franz Narberhaus
Institute of Microbial Biology, IGB; Ruhr-Universität Bochum, 44780 Bochum, Germany
e-mail: annika.cimdins@rub.de
According to their preferred growth temperature, bacteria can be divided into groups. Those
preferring moderate growth temperatures (optimum around 37°C) belong to the mesophiles,
whereas bacteria living in warmer habitats (up to ~80°C) are called thermophiles. To avoid
hazardous consequences, free-living bacteria have to constantly monitor and respond to
temperature changes. RNA thermometers provide a direct way of sensing temperature shifts
and immediately responding to them. RNA thermometers are cis-acting elements in the
5´untranslated region (5´UTR) of the mRNA of genes involved in the heat shock response or
in virulence. At low temperatures, the mRNA folds into a complex structure, thereby blocking
the ribosome binding site (RBS) via base pairing. Thus, translation is inhibited. Due to an
upshift in temperature, the structure melts, liberating the RBS and enabling formation of the
translation initiation complex [1]. Here, we present two extraordinary RNA thermometers,
both being involved in regulation of the heat shock response. The first one, located in the
5´UTR of the htrA-mRNA in Salmonella, represents an exceptionally short RNA
thermometer. The second one originates from the thermophilic cyanobacterium
Thermosynechococcus elongatus and regulates translation of the hspA-mRNA, thereby being
the first known thermophilic RNA thermometer.
References
[1] Klinkert, B. and Narberhaus, F., Cell Mol Life Sci, 2009, 66, 2661-2676.