Search results
Results From The WOW.Com Content Network
Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum. Their main function is to convert genetic code into an amino acid sequence and to build protein polymers from amino acid monomers. Ribosomes act as catalysts in two extremely important biological processes called peptidyl transfer and peptidyl hydrolysis.
The cloverleaf model of tRNA is a model that depicts the molecular structure of tRNA. [1] The model revealed that the chain of tRNA consists of two ends—sometimes called "business ends"—and three arms. Two of the arms have a loop, D-loop (dihydro U loop) and Tψc-loop with a ribosome recognition site.
Molecules can be displayed in different styles of rendering, like ball-and-stick models, space-filling models, ribbon diagrams, molecular surfaces, etc. [7] Jmol supports a wide range of chemical file formats, including Protein Data Bank (pdb), Crystallographic Information File (cif and mmcif), MDL Molfile (mol and sdf), and Chemical Markup ...
The ribosome must discriminate between correct and incorrect codon-anticodon pairs. It does so, in part, through the insertion of adenine bases into the minor groove. Incorrect codon-anticodon pairs will present distorted helical geometry, which will prevent the A-minor interaction from stabilizing the binding, and increase the dissociation ...
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:
Initial structures of eukaryotic ribosomes were determined by electron microscopy. First 3D structures were obtained at 30–40 Å resolution for yeast [5] and mammalian ribosomes. [6] [7] Higher resolution structures of the yeast ribosome by cryo-electron microscopy allowed the identification of protein and RNA structural elements. [8]
3D printed model of the structure of a bacterial flagellum "motor" and partial rod structure of a Salmonella species. Bottom to top: dark blue, repeating FliM and FliN, motor/switch proteins; red, FliG motor/switch proteins; yellow, FliF transmembrane coupling proteins; light blue, L and P ring proteins; and (at top), dark blue, the cap, hook-filament junction, hook, and rod proteins.
The range of conformations adopted by tRNA as it transits the A/T through P/E sites on the ribosome. The Protein Data Bank (PDB) codes for the structural models used as end points of the animation are given. Both tRNAs are modeled as phenylalanine-specific tRNA from Escherichia coli, with the A/T tRNA as a homology model of the deposited ...