Search results
Results from the WOW.Com Content Network
The eukaryotic small ribosomal subunit (40S) is the smaller subunit of the eukaryotic 80S ribosomes, with the other major component being the large ribosomal subunit (60S). The "40S" and "60S" names originate from the convention that ribosomal particles are denoted according to their sedimentation coefficients in Svedberg units .
The ribosome catalyzes ester-amide exchange, transferring the C-terminus of a nascent peptide from a tRNA to the amine of an amino acid. These processes are able to occur due to sites within the ribosome in which these molecules can bind, formed by the rRNA stem-loops. A ribosome has three of these binding sites called the A, P and E sites:
The complete structure of the eukaryotic 80S ribosome from the yeast Saccharomyces cerevisiae was obtained by crystallography at 3.0 A resolution. [18] These structures reveal the precise architecture of eukaryote-specific elements, their interaction with the universally conserved core, and all eukaryote-specific bridges between the two ...
Ribosomes are the macromolecular machines that are responsible for mRNA translation into proteins. The eukaryotic ribosome, also called the 80S ribosome, is made up of two subunits – the large 60S subunit (which contains the 25S [in plants] or 28S [in mammals], 5.8S, and 5S rRNA and 46 ribosomal proteins) and a small 40S subunit (which contains the 18S rRNA and 33 ribosomal proteins). [6]
In the figure "Crystal Structure of the Eukaryotic 60S Ribosomal Subunit from T. thermophila", the ribosomal RNA core is represented as a grey tube and expansion segments are shown in red. Proteins which have homologs in eukaryotes, archaea and bacteria are shown as blue ribbons.
The 5S ribosomal RNA (5S rRNA) is an approximately 120 nucleotide-long ribosomal RNA molecule with a mass of 40 kDa.It is a structural and functional component of the large subunit of the ribosome in all domains of life (bacteria, archaea, and eukaryotes), with the exception of mitochondrial ribosomes of fungi and animals.
The 30S subunit is an integral part of mRNA translation.It binds three prokaryotic initiation factors: IF-1, IF-2, and IF-3. [3]A portion of the 30S subunit (the 16S rRNA) guides the initiating start codon (5′)-AUG-(3′) of mRNA into position by recognizing the Shine-Dalgarno sequence, a complementary binding site about 8 base pairs upstream from the start codon. [4]
The general molecular structure of the ribosome has been known since the early 1970s. In the early 2000s, the structure has been achieved at high resolutions, of the order of a few ångströms. The first papers giving the structure of the ribosome at atomic resolution were published almost simultaneously in late 2000.