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A ribosome is an organelle composed of ribosomal RNA and ribosomal proteins (known as a Ribonucleoprotein or RNP). It translates Messenger RNA (mRNA) into a polypeptide chain (e.g., a protein). It can be thought of as a factory that builds a protein from a set of genetic instructions. Ribosomes can float freely in the cytoplasm (the internal fluid of the cell) or bind to the endoplasmic reticulum, or to the nuclear envelope. Since ribosomes are ribozymes, it is thought that they might be remnants of the RNA world.
The structure and function of the ribosomes and associated molecules, known as the translational apparatus, has been of research interest since the mid 20th century and is a very active field of study today.
Overview
Ribosomes consist of two subunits (Figure 1) that fit together (Figure 2) and work as one to translate the mRNA into a polypeptide chain during protein synthesis (Figure 3). Prokaryotic subunits consist of one or two and eukaryotic of one or three very large RNA molecules (known as ribosomal RNA or rRNA) and multiple smaller protein molecules. Crystallographic work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis. This suggests that the protein components of ribosomes act as a scaffold that may enhance the ability of rRNA to synthesise protein rather than directly participating in catalysis. (See: Ribozyme) More on [ Ribosome ]
Gene Expression :: Biochemistry and Molecular Biology
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Introduction to the Ribosome - Overview of structure, role, including bacterial antibiotic resistance, and mechanism of action. Includes glossary and technology for structure based drug design at Pharmaceuticals Inc, New Haven, CT.
Ribosomal Database Project - RDP II now includes a comprehensive tutorial for data analysis, rRNA derived phylogenetic trees, and aligned and annotated rRNA sequences, maintained at the Center for Microbial Ecology, MSU, East Lansing, MI.
Meta Description: [ The organization, research and educational activities, and personnel of the
MSU Center for Microbial Ecology, an National Science Foundation science and technolology center. ]
Ribosomes Revealed - Article, with links to researchers, on elucidating structure of ribosomal RNA from X-ray crystallagraphy, and their function at the Department of Chemistry and Biochemistry, St. Edward's University, Austin, TX.
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Subsynaptic Ribosomes - Their distribution and role in the brain, with micrographs, 3D-images and references, part of Synapse Web by Josef Spacek at Medical College of Georgia, Augusta.
Meta Description: [ Tutorial on the distribution of subsynaptic ribosomes in the brain by Josef Spacek ]
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White: Structural Studies of the Prokaryotic Ribosome - Research on the complex between RNA and ribosomal protein, S4-RNA interaction surface and thiostrepton binding site, at St Judes Children's Hospital, Memphis, TN.
Meta Description: [ Research in Structural Biology by Stephen White, DPhil. ]
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