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NEWS
March 2025 ESRFnews
Researchers have visualised for the
first time how mRNA is delivered to the
ribosome to begin the production of
proteins – thanks in part to the ESRF’s
cryo-electron microscopy (cryo-EM)
facility.
Our DNA holds the instructions for
making proteins, which are essential
for the body to function. To use these
instructions, a molecular machine
called RNA polymerase (RNAP)
copies the relevant section of DNA into
a short-lived copy called messenger
RNA (mRNA). This mRNA carries
the instructions to another molecular
machine, the ribosome. In bacteria,
these two steps happen at the same
time, allowing RNAP and the ribosome
to cooperate and regulate each other.
A team led by Albert Weixlbaumer at
the Institut de Génétique et de Biologie
Moléculaire et Cellulaire (IGBMC)
in Strasbourg, France, wanted to
know how bacterial ribosomes are
recruited to mRNAs while they are still
transcribed by RNAP. Using cryo-EM
at both the ESRF and at the IGBMC,
they could visualise the ribosome-
mRNA assemblies at molecular
resolution (Science 386 6725).
“It’s a real pleasure to work with the
scientists at the ESRF,” says Albert
Weixlbaumer, IGBMC scientist and
leader of the research project. “We
always feel that they’re very dedicated
to the projects they support. The
quality and amount of data we obtain
could not be better.”
The next question for the team is
how RNAP and the ribosome are able
to regulate each other’s activities.
Protein production
visualised
Scientists have published the first
results from the ESRF’s new ID14
nuclear-resonance beamline and the
high-power laser facility (HPLF).
The ID14 results concern osmium,
a rare transition metal, which is
gaining interest in anticancer
research as an alternative to
platinum-based chemotherapy
drugs. Although osmium complexes
with different osmium oxidation
states have shown promise, their
mechanisms of action have been
unclear, and none has been approved
for medical use Now researchers
at the University of Vienna in
Austria KU Leuven Belgium and
Roosevelt University in the US have
shown that synchrotron Mössbauer
spectroscopy at ID14 is powerful
enough to probe
187
Os directly for
the study of osmium complexes in
contrast to conventional Mössbauer
spectroscopy based on
189
Os which
relies on a very short lived radioactive
source Sci Adv 11 eads3406 I
do not know other beamlines where
investigation of
187
Os compounds
can be performed,” says Vladimir
Arion, one of the study’s authors.
Another author, Gabriel Büchel,
says: “It will hopefully show us the
transformations of osmium-based
prodrugs in ‘real world’ environments
– namely cell culture media, the
extracellular matrix, cellular
cytoplasm and the cell nucleus.”
Meanwhile, ESRF PhD student
Sofia Balugani and her colleagues
have used the new HPLF to shock-
compress iron up to a pressure of
270 GPa and a temperature of
5800 K to understand how it behaves
in conditions approaching those of
the Earths core As a result they
were able to determine the melting
temperature of iron near this high
pressure and confirm that it retains
a hexagonalclosepacked structure
prior to melting rather than switch
to a bodycenteredcubic phase which
had been speculated Their paper has
been selected for its journals 2024
Collection a distinction given to
only 2 of the journals publications
Phys Rev Lett 133 254101
Gabriel Büchel (left) and Dimitrios Bessas at the beamline during the ID14 experiment.
E S R F/ S T E F C A N D É
ID14 and ID24-HPLF f irst results
W E B S T E R, M. W., E T A L.
Ribosome recruitment to an mRNA that is still
being synthesised by RNA polymerase.
“The HPLF
has been used
to shock-
compress iron
to understand
how it behaves
in conditions
approaching
those of the
Earth’s core”