|
EF2
Elongation factors are a set of proteins that function at the ribosome, during protein synthesis, to facilitate translational elongation from the formation of the first to the last peptide bond of a growing polypeptide. Most common elongation factors in prokaryotes are EF-Tu, EF-Ts, EF-G. Bacteria and eukaryotes use elongation factors that are largely homologous to each other, but with distinct structures and different research nomenclatures. Elongation is the most rapid step in translation. In bacteria, it proceeds at a rate of 15 to 20 amino acids added per second (about 45-60 nucleotides per second). In eukaryotes the rate is about two amino acids per second (about 6 nucleotides read per second). Elongation factors play a role in orchestrating the events of this process, and in ensuring the high accuracy translation at these speeds. Nomenclature of homologous EFs In addition to their cytoplasmic machinery, eukaryotic mitochondria and plastids have their own translation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EF-G
EF-G (elongation factor G, historically known as translocase) is a prokaryotic elongation factor involved in mRNA translation. As a GTPase, EF-G catalyzes the movement (translocation) of transfer RNA (tRNA) and messenger RNA (mRNA) through the ribosome. Structure Encoded by the ''fusA'' gene on the ''str'' operon, EF-G is made up of 704 amino acids that form 5 domains, labeled Domain I through Domain V. Domain I may be referred to as the G-domain or as Domain I(G), since it binds to and hydrolyzes guanosine triphosphate (GTP). Domain I also helps EF-G bind to the ribosome, and contains the N-terminal of the polypeptide chain. Domain IV is important for translocation, as it undergoes a significant conformational change and enters the A site on the 30S ribosomal subunit, pushing the mRNA and tRNA molecules from the A site to the P site. The five domains may be also separated into two super-domains. Super-domain I consists of Domains I and II, and super-domain II consists of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EEF-2
Eukaryotic elongation factor 2 is a protein that in humans is encoded by the ''EEF2'' gene. It is the archaeal and eukaryotic counterpart of bacterial EF-G. This gene encodes a member of the GTP-binding translation elongation factor family. This protein is an essential factor for protein synthesis. It promotes the GTP-dependent translocation of the ribosome. This protein is completely inactivated by EF-2 kinase phosphorylation. aEF2/eEF2 found in most archaea and eukaryotes, including humans, contains a post translationally modified histidine diphthamide. It is the target of diphtheria toxin (from ''Corynebacterium diphtheriae''), and exotoxin A (from ''Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common Bacterial capsule, encapsulated, Gram-negative bacteria, Gram-negative, Aerobic organism, aerobic–facultative anaerobe, facultatively anaerobic, Bacillus (shape), rod-shaped bacteria, bacterium that can c ...''). The inactivation of EF-2 by toxins inhibits protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphtheria Toxin
Diphtheria toxin is an exotoxin secreted mainly by '' Corynebacterium diphtheriae'' but also by ''Corynebacterium ulcerans'' and '' Corynebacterium pseudotuberculosis'', the pathogenic bacterium that causes diphtheria. The toxin gene is encoded by a prophageA prophage is a virus that has inserted itself into the genome of the host bacterium. called corynephage β. The toxin causes the disease in humans by gaining entry into the cell cytoplasm and inhibiting protein synthesis. Structure Diphtheria toxin is a single polypeptide chain of 535 amino acids consisting of two subunits linked by disulfide bridges, known as an A-B toxin. Binding to the cell surface of the B subunit (the less stable of the two subunits) allows the A subunit (the more stable part of the protein) to penetrate the host cell. The crystal structure of the diphtheria toxin homodimer has been determined to 2.5 Ångstrom resolution. The structure reveals a Y-shaped molecule consisting of three domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EF-Tu
EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome. It is a G-protein, and facilitates the selection and binding of an aa-tRNA to the A-site of the ribosome. As a reflection of its crucial role in translation, EF-Tu is one of the most abundant and highly conserved proteins in prokaryotes. It is found in eukaryotic mitochondria as TUFM. As a family of elongation factors, EF-Tu also includes its eukaryotic and archaeal homolog, the alpha subunit of eEF-1 (EF-1A). Background Elongation factors are part of the mechanism that synthesizes new proteins through translation in the ribosome. Transfer RNAs (tRNAs) carry the individual amino acids that become integrated into a protein sequence, and have an anticodon for the specific amino acid that they are charged with. Messenger RNA (mRNA) carries the genetic information that encodes the primary structure of a protein, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GUF1
Mitochondrial GTP binding elongation factor (''Homo Sapiens'', GUF1), is a protein which in humans is encoded by the ''GUF1'' gene. The GUF1 protein plays an important role in maintaining proper mitochondrial function, ensuring accuracy when mitochondrial genes are being translated. The gene shows the most expression in the brain, while the least expression is found in the pancreas. Function and biochemistry GUF1 is a GTPase that Hydrolysis, hydrolyzes GTP to GDP and plays an important role in maintaining mitochondrial function by ensuring accurate translation of mitochondrial genes. It helps prevent amino acid mis-incorporation under stress by facilitating ribosomal back-translocation during protein synthesis. Additionally, its C-terminal region aids in tRNA interaction, distinguishing it from other GTPases. The highly conserved C-terminal of GUF1 facilitates tRNA binding, while the N-terminal handles GTP binding and hydrolysis. The G domain supports core GTPase activity. Gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
