Protein biosynthesis
hideProtein synthesis is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA which is then used as input to translation.
The cistron DNA is transcribed into a variety of RNA intermediates. The last version is used as a template in synthesis of a polypeptide chain. Proteins can often be synthesized directly from genes by translating mRNA. When a protein is harmful and needs to be available on short notice or in large quantities, a protein precursor is produced. A proprotein is an inactive protein containing one or more inhibitory peptides that can be activated when the inhibitory sequence is removed by proteolysis during posttranslational modification. A preprotein is a form that contains a signal sequence (an N-terminal signal peptide) that specifies its insertion into or through membranes; i.e., targets them for secretion. The signal peptide is cleaved off in the endoplasmic reticulum.. Preproproteins have both sequences (inhibitory and signal) still present.
For synthesis of protein, a succession of tRNA molecules charged with appropriate amino acids have to be brought together with an mRNA molecule and matched up by base-pairing through their anti-codons with each of its successive codons. The amino acids then have to be linked together to extend the growing protein chain, and the tRNAs, relieved of their burdens, have to be released. This whole complex of processes is carried out by a giant multimolecular machine, the ribosome, formed of two main chains of RNA, called ribosomal RNA (rRNA), and more than 50 different proteins. This molecular juggernaut latches onto the end of an mRNA molecule and then trundles along it, capturing loaded tRNA molecules and stitching together the amino acids they carry to form a new protein chain.
Protein biosynthesis, although very similar, is different for prokaryotes and eukaryotes.
For more information about Protein biosynthesis, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with protein synthesis
New activity found for a potential anti-cancer agent
Nov 02, 2009 |
not rated yet |
0
Pateamine A (PatA), a natural product first isolated from marine sponges, has attracted considerable attention as a potential anti-cancer agent, and now a new activity has been found for it, which may reveal yet another anti-cancer ...
Moderate amounts of protein per meal found best for building muscle
Oct 26, 2009 |
5 / 5 (3) |
0
For thousands of years, people have believed that eating large amounts of protein made it easier to build bigger, stronger muscles. Take Milo of Croton, the winner of five consecutive Olympic wrestling championships in the ...
New research shows how mobile DNA survives -- and thrives -- in plants, animals
Oct 21, 2009 |
not rated yet |
0
(PhysOrg.com) -- Bits of movable DNA called transposable elements or TEs fill up the genomes of plants and animals, but it has remained unclear how a genome can survive a rapid burst of hundreds, even thousands of new TE ...
Study identifies two chemicals that could lead to new drugs for genetic disorders
Sep 28, 2009 |
5 / 5 (1) |
0
UCLA scientists have identified two chemicals that convince cells to ignore premature signals to stop producing important proteins. Published in the Sept. 28 edition of the Journal of Experimental Medicine, the findings could ...
Insulin boost restores muscle growth in elderly
Sep 25, 2009 |
5 / 5 (7) |
1
When most people think of insulin, they think of diabetes — a disease that arises when, for one reason or another, insulin can't do the critical job of helping the body process sugar. But the hormone has another, less well-known ...
Experiments show 'artificial gravity' can prevent muscle loss in space
Jul 22, 2009 |
3 / 5 (2) |
4
When the Apollo 11 crew got back from the moon, 40 years ago this week, they showed no ill effects from seven days spent in weightlessness. But as American astronauts and Soviet cosmonauts began conducting longer-duration ...
Researchers Reveal Structure of Key Genetic Proofreading Protein
Jun 05, 2009 |
5 / 5 (2) |
0
(PhysOrg.com) -- Nature might abhor a vacuum, but it loves a backup plan. In living organisms, physiological systems are kept under tight control by hierarchies of organic safety catches and emergency releases, ...
Cereal and milk is the new sports supplement
May 14, 2009 |
5 / 5 (2) |
0
Exercise physiologist Lynne Kammer, from The University of Texas at Austin, led a group of researchers who investigated the post-exercise physiological effects of the foods. Kammer and her team studied 12 trained cyclists, ...
Key protein in cellular respiration discovered
Apr 08, 2009 |
5 / 5 (2) |
0
Many diseases derive from problems with cellular respiration, the process through which cells extract energy from nutrients. Researchers at the Swedish medical university Karolinska Institutet have now discovered a new function ...
Master Molecular Switch May Prevent the Spread of Cancer Cells to Distant Sites in the Body
Mar 16, 2009 |
4.8 / 5 (6) |
1
Researchers at the University of Pennsylvania School of Medicine have identified a master switch that might prevent cancer cells from metastasizing from a primary tumor to other organs. The switch is a protein ...
Well-known enzyme is unexpected contributor to brain growth
Medicine & Health / Neuroscience
Mar 12, 2009 |
5 / 5 (2) |
0
An enzyme researchers have studied for years because of its potential connections to cancer, diabetes, heart disease, hypertension and stroke, appears to have yet another major role to play: helping create and maintain the ...
'Fishy' clue helps establish how proteins evolve
Biology /
Jan 27, 2009 |
4.2 / 5 (5) |
0
(PhysOrg.com) -- Three billion years ago, a "new" amino acid was added to the alphabet of 20 that commonly make up proteins in organisms today. Now researchers at Yale and the University of Tokyo have demonstrated ...
Study finds more effective treatment for pneumonia following influenza
Jan 08, 2009 |
5 / 5 (1) |
0
Scientists at St. Jude Children's Research Hospital have demonstrated a more effective treatment for bacterial pneumonia following influenza. They found that the antibiotics clindamycin and azithromycin, which kill bacteria ...
Study reveals surprising details of the evolution of protein translation
Biology /
Aug 12, 2008 |
4.6 / 5 (10) |
0
A new study of transfer RNA, a molecule that delivers amino acids to the protein-building machinery of the cell, challenges long-held ideas about the evolutionary history of protein synthesis.
Animal study suggests inadequate sleep may exacerbate cellular aging in the elderly
Jun 27, 2008 |
5 / 5 (1) |
0
Researchers at the University of Pennsylvania School of Medicine have shown that the unfolded protein response, which is a reaction to stress induced by sleep deprivation, is impaired in the brains of old mice.
- Pages: 1
