Search results
Results from the WOW.Com Content Network
50S, roughly equivalent to the 60S ribosomal subunit in eukaryotic cells, is the larger subunit of the 70S ribosome of prokaryotes. The 50S subunit is primarily composed of proteins but also contains single-stranded RNA known as ribosomal RNA (rRNA). rRNA forms secondary and tertiary structures to maintain the structure and carry out the catalytic functions of the ribosome.
The DNA for the 5S subunit occurs in tandem arrays (~200–300 true 5S genes and many dispersed pseudogenes), the largest one on the chromosome 1q41-42. 5S rRNA is transcribed by RNA polymerase III. The 18S rRNA in most eukaryotes is in the small ribosomal subunit, and the large subunit contains three rRNA species (the 5S , 5.8S and 28S in ...
Each subunit is made of one or more rRNAs and many r-proteins. The small subunit (30S in bacteria and archaea, 40S in eukaryotes) has the decoding function, whereas the large subunit (50S in bacteria and archaea, 60S in eukaryotes) catalyzes the formation of peptide bonds, referred to as the peptidyl-transferase activity.
The peptidyl transferase center is a significant piece of evidence supporting the RNA World hypothesis. [2] In prokaryotes, the 50S (23S component) ribosomal subunit contains the peptidyl transferase center and acts as a ribozyme. The peptidyl transferase center on the 50S subunit lies at the lower tips (acceptor ends) of the A- and P- site tRNAs.
The ribosome of E. coli has about 22 proteins in the small subunit (labelled S1 to S22) and 33 proteins in the large subunit (somewhat counter-intuitively called L1 to L36). All of them are different with three exceptions: one protein is found in both subunits (S20 and L26), [ dubious – discuss ] L7 and L12 are acetylated and methylated forms ...
The initiation phase is completed once a 50S subunit joins the 30S subunit, forming an active 70S ribosome. [11] Termination of the polypeptide occurs when the A site of the ribosome is occupied by a stop codon (UAA, UAG, or UGA) on the mRNA, creating the primary structure of a protein. tRNA usually cannot recognize or bind to stop codons.
This ribosomal protein is a component of the 50S subunit. The protein binds 5S rRNA to form a stable complex. In turn 5S rRNA binds specifically to three proteins, L25, L18 and L5, forming a separate domain of the bacterial ribosome. [1] Protein L25 of E. coli is not essential for survival of the cells. [2] [3]
Large subunit ribosomal ribonucleic acid (LSU rRNA) is the largest of the two major RNA components of the ribosome. Associated with a number of ribosomal proteins, the LSU rRNA forms the large subunit of the ribosome. The LSU rRNA acts as a ribozyme, catalyzing peptide bond formation