In 1981 Thomas Cech watches an RNA molecule from Tetrahymena cut itself out of a transcript using only RNA.
The Visitor arrives at the ribosome and finds that its working core is RNA.
The Catalytic Core Is RNA
- Before 1981 biology assigned storage to DNA, copying to RNA, and chemistry to proteins. Cech's discovery gave RNA a catalytic role, and the page names such RNAs ribozymes (Nobel Prize 1989).
- The ribosome's peptidyl transferase center, which forms every peptide bond, is RNA. Steitz, Moore, and Ramakrishnan established this (Nobel Prize 2009).
- The large subunit (60S) holds the 28S rRNA of 3,375 nucleotides, and about 49 ribosomal proteins assist. The small subunit (40S) holds the 18S rRNA of 1,869 nucleotides, which forms the decoding center, with about 33 proteins assisting.
- The page describes a circle: the ribosome needs ribosomal proteins to fold its RNA into the catalytic shape, and the ribosome makes those proteins. The page names this circle Eigen's Paradox made physical.
The ribosome walks the message while the chain grows from the RNA core at its center. The site page carries the subunit counts and the circle.
Which part of the ribosome forms peptide bonds, and what is it made of?
The peptidyl transferase center in the large subunit, made of RNA.
The ribosome's catalytic core is RNA, so one kind of molecule carries information and performs chemistry.
The Visitor lights node 08. RNA Regulation and Ribozymes glow as a pair.
See the map