 |
| Space
filled model of a 70S ribosome. |
Now that scientists have determined
most of the sequence of chemical units
in the human genome, a next step is
to unravel the mechanisms directed
by the genetic code. Scientists got
a close look at some of these mechanisms
recently by using synchrotron light
sources to make images of RNA polymerase,
both subunits of the ribosome, and
the full ribosome. These "molecular
machines" read the genetic message
and accurately make the proteins that
form the structures and perform the
functions of living organisms. These
assemblies have been the subjects
of intense study for 30 years, but
only recently have advances in synchrotron
technology, crystal sample quality,
experimental methods, and computational
approaches enabled near-atomic resolution
of their structures. The new images
reveal in minute detail how DNA is
unwound, how a message (mRNA) is created
with the help of RNA polymerase, how
this message is read by a ribosome,
and how the ribosome synthesizes protein.
The image of the complete ribosome
was named by Science magazine
as one of the top 10 scientific breakthroughs
of 1999. The work was performed at
Lawrence Berkeley National Laboratory,
Argonne National Laboratory, and Stanford
Synchrotron Radiation Laboratory.
Scientific Impact:
These images demonstrated that there
is much more to ribosomal structures
than previously thought. They also
helped bolster the theory that RNA
molecules were among life's first,
with proteins emerging at a later
time.
Social Impact: Studies
of this type are expected to help
lay the groundwork for improved drug
design, faster diagnosis of disease,
and better disease prevention and
treatment methods.
Reference: Jamie
H. Cate, Marat M. Yusupov, Gulnara
Zh. Yusupova, Thomas N. Earnest, and
Harry F. Noller, "X-ray Crystal Structures
of 70S Ribosome Functional Complexes,"
Science 285: 2095-2104 (1999).
Technical Contact:
Dr. Roland Hirsch, Medical Sciences
Division, Office of Biological and
Environmental Research, 301-903-9009
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Biological and Environmental
Research |
