From Simple English Wikipedia, the free encyclopedia
Sir Richard John Roberts
FRS
(born 6 September 1943,
Derby
) is a
British
biochemist
and
molecular biologist
.
He was awarded the 1993
Nobel Prize in Physiology or Medicine
with
Phillip Sharp
for "the discovery that
genes
in
eukaryotes
are not contiguous strings but contain
introns
, and that the splicing of
messenger RNA
to delete those introns can occur in different ways, yielding different proteins from the same DNA sequence".
[1]
Roberts has worked at
Harvard University
,
Cold Spring Harbor Laboratory
and New England Biolab. He was
knighted
in the 2008 Birthday Honours.
[2]
It used to be thought that each
gene
on
DNA
coded for a single
protein
in a continuous strip. Roberts and Sharp independently found out that the genes in
adenovirus
(which causes the
common cold
), were split into segments that were combined later in
RNA
processing.
In 1997 Roberts proved that in the adenovirus coding DNA is separated by stretches of DNA which are non-coding. The coding sections are
exons
, and the non-coding sections are
introns
.
Furthermore, it turned out that this structure occurs in all higher organisms. The discovery that a gene in could be present in the genetic material as several distinct and separate segments was revolutionary.
The second part of Robert's work was in gene-splitting and gene splicing. This means to cut pieces out of, and add pieces to, a coding sequence. This creates a protein which works differently from the original version.
[3]
This is now used in
genetic engineering
.
This kind of structure may allow more flexible responses to
environmental
change, and so speed up
evolution
. The structure may also be responsible for a number of inherited genetic defects.
Here's a key part of the Nobel presentation speech by Professor Bertil Daneholt of the Nobel Assembly of the Karolinska Institute:
- "Earlier it was believed that genes evolve mainly through the accumulation of small discrete changes in the genetic material. But their mosaic gene structure also permits higher organisms to restructure genes in another, more efficient way. This is because during the course of evolution, gene segments - the individual pieces of the mosaic - are regrouped in the genetic material, which creates new mosaic patterns and hence new genes. This reshuffling process presumably explains the rapid evolution of higher organisms".
[4]
- ↑
Gene-splicing is cutting out part of a genetic code, with 'restriction enzymes', and adding new code into the gap. Another enzyme called a 'ligase' sticks the pieces of RNA together. The end product now has a changed function.
- ↑
Autobiography:
Nobel Prize website
Archived
2008-10-22 at the
Wayback Machine
- ↑
Shampo, Marc A.; Kyle, Robert A.; Vasilev, V. (2003). "Richard J. Roberts--Nobel Laureate for discovery of split genes".
Mayo Clin. Proc
.
78
(2): 48?52.
doi
:
10.4065/78.2.132
.
PMID
1258352
.
- ↑
Laurence A. Moran's Sandwalk
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1901 ? 1925
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1926 ? 1950
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1951 ? 1975
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1976 ? 2000
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2001 ? present
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