News tagged with protein synthesis

Related topics: rna molecules , protein , gene expression , amino acids , messenger rna

Rett syndrome gene dysfunction redefined

Whitehead Institute researchers have redefined the function of a gene whose mutation causes Rett syndrome, a neurodevelopmental autism spectrum disorder. This new research offers an improved understanding of the defects found ...

Oct 03, 2013
popularity 5 / 5 (6) | comments 0 | with audio podcast

A better way to remember

Scientists and educators alike have long known that cramming is not an effective way to remember things. With their latest findings, researchers at the RIKEN Brain Science Institute in Japan, studying eye ...

Jun 17, 2011
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Researchers target an aspect of Down syndrome

University of Michigan researchers have determined how a gene that is known to be defective in Down syndrome is regulated and how its dysregulation may lead to neurological defects, providing insights into ...

Jun 05, 2013
popularity 5 / 5 (3) | comments 0 | with audio podcast

Protein biosynthesis

Protein 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.

This text uses material from Wikipedia licensed under CC BY-SA