US biochemist who was awarded the Nobel Prize for Chemistry in 1989 with Sidney Altman for his discovery of the catalytic activity of RNA whilst working on introns, regions of genes that do not contain genetic information.
It was thought that DNA served as templates for messenger RNA (mRNA) molecules, and that these mRNA molecules were themselves direct templates for protein synthesis. However, before the protein could be translated from the messenger RNA, the introns (non-coding regions) had to be spliced out. Cech believed that an enzyme must be involved in this splicing.
He took nuclei from the ciliate Tetrahymena thermophilia and mixed them together with some unspliced RNA. As he expected, the RNA introns were snipped away, but surprisingly none of the nuclear enzymes had been used. He deduced that the protein-free precursor ribosomal RNA mediates its own cleavage and splicing. Cech called this and other catalytic forms of RNA ribozymes.
Cech was born in Chicago and educated at the universities of California and Chicago. He worked briefly at the Massachusetts Institute of Technology before becoming a professor at the University of Colorado, Boulder, in 1983.
Cech also postulated that RNA splicing was at the forefront of creation and that it initiated evolution. His work continued, encompassing the action of telomerase enzymes, which use an inbuilt template to add short repeat sections of DNA to chromosomal DNA.
In March 1999 Cech was named as the next president of the Howard Hughes Medical Institute, the USA's largest research philanthropy that contributes $420 million to scientific research programmes.
In genetics, a stretch of DNA that interrupts the coding parts (exons) of a gene but apparently carries no genetic information. Introns, discovered i
US molecular biologist who was awarded a Nobel Prize for Physiology or Medicine in 1993 with Richard Roberts for their discovery of split genes (gene
a mechanism in which different combinations of exons are joined together during the final stages of transcription so that more than one messenger RN