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 protein key for cell proliferation identified
Dec 14, 2009 |
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(PhysOrg.com) -- Researchers at McGill University have identified a protein that plays a key role in cell proliferation and is likely to promote cancer development. The work may lead to the development of new diagnostic tools ...
Scientists crack mystery of protein's dual function
Dec 13, 2009 |
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Researchers at The Scripps Research Institute have solved a 10-year-old mystery of how a single protein from an ancient family of enzymes can have two completely distinct roles in the body. In addition to providing guidance ...
Researchers design a tool to induce controlled suicide in human cells
Dec 17, 2009 |
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When cells accumulate excessive errors in the proteins they produce, apoptosis is activated, that is to say, a cell suicide programme; however, beforehand the cells attempt to rectify the problem through a number of rescue ...
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Watching Proteins Direct Crystal Growth One Step at a Time (w/ Video)
Dec 16, 2009 |
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(PhysOrg.com) -- Scientists at Berkeley Lab's Molecular Foundry imaged the growth of protein-studded mineral surfaces with unprecedented resolution and provided a glimpse into how living systems engineer key ...
Undergrad researchers lay groundwork for drug addiction remedy
Dec 08, 2009 |
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Sarah Steele and Langtian "Ren" Yuan were both self-admittedly inexperienced Duke freshmen in the spring of 2006. But then they followed helpful directions of an assistant chemistry professor, added their own patience and ...
Drug shows promise for T315I-mutated chronic myeloid leukemia
Dec 07, 2009 |
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Results from a phase II clinical trial indicate a novel drug may provide a treatment option for chronic myeloid leukemia (CML) patients who do not respond to current therapies, researchers from The University of Texas M. ...
Researchers restore some function to cells from cystic fibrosis patients
Dec 06, 2009 |
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In an encouraging new development, a team led by Scripps Research Institute scientists has restored partial function to lung cells collected from patients with cystic fibrosis. While there is still much work to be done before ...
Researchers develop cheap, easy 'kitchen chemistry' to perform formerly complex synthesis
Chemistry / Analytical Chemistry
Dec 04, 2009 |
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A team at The Scripps Research Institute has made major strides in solving a problem that has been plaguing chemists for many years: how best to break carbon-hydrogen bonds and then to create new bonds to join molecules together. ...
New understanding about mechanism for cell death after stroke leads to possible therapy
Nov 22, 2009 |
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Scientists at the Brain Research Centre, a partnership of the University of British Columbia Faculty of Medicine and Vancouver Coastal Health Research Institute, have uncovered new information about the mechanism by which ...
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