This is a submission from UC Davis CBS Professor Sean Burgess. It comes from a future publication that relates the human quest to visualize the inner workings of the cell, molecular biology, with the quest to visualize the interior of the mind, art.
The Eukaryotic Ribosome
The basic mechanism of ribosomebased protein synthesis is conserved among all domains of life. The ribosome comes in two parts. The small subunit interacts with the mRNA and decodes the interaction with the aminoacyl tRNAs. The large subunit contains the active site of peptidyl transferase. The two subunits together
form three pockets for three forms of tRNA. The A site is where the aminoacyl tRNA binds, the P site holds that peptidyl tRNA when the Asite is occupied. The E site contains the deacylated tRNA following peptidyl transferase. The ribosome is a huge conglomeration of RNA and proteins. The RNA appears to do all the heavy lifting for the main catalytic event of protein synthesis. So what came first, the protein or the ribosome?
Obtaining the crystal structure of the ribosome was a tour de force effort. The Nobel Prize for solving its structure was awarded in 2009.
Top: Willi Baumeister: Mortaruru with Red Overhead (1953), The Art Book,
Phaidon Press Limited, 1994.
Bottom: The 60S (PDB: 305H) and 40S (PDB: 1S1H) subunits of the eukaryotic ribosome. BenShem et al. (2010) Science, 330 (6008): 12031209. The image was generated by S.M.B. using MacPymol using coordinates from the Protein Databank (http://helixweb.nih.gov/cgibin/pdb). MacPyMOL is product of
Schrodinger, LLC. Copyright (C) 20092010.