TransloconThe translocon (also called a translocator or translocation channel) is a general term for a protein channel in biological membranes that functions to move polypeptides across the membrane or insert them into the lipid bilayer. This structure is a key component of the protein translocation pathway in all organisms, from bacteria, archaea, and eukaryotes.SecDF protein-export membrane proteinSecD and SecF are prokaryotic protein export membrane proteins. They are a part of the larger multimeric protein export complex comprising SecA, D, E, F, G, Y, and YajC. SecD and SecF are required to maintain a proton motive force. Secretion across the inner membrane in some Gram-negative bacteria occurs via the preprotein translocase pathway. Proteins are produced in the cytoplasm as precursors, and require a chaperone subunit to direct them to the translocase component.
Cell membraneThe cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a semipermeablebiological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space).SecAThe SecA protein is a cell membrane associated subunit of the bacterial Sec or Type II secretory pathway, a system which is responsible for the secretion of proteins through the cell membrane. Within this system the SecA ATPase forms a translocase complex with the SecYEG channel, thereby driving the movement of the proteinsubstrate across the membrane.
SecY proteinThe SecY protein is the main transmembrane subunit of the bacterial Sec export pathway and of a protein-secreting ATPase complex, also known as a SecYEGtranslocon. Homologs of the SecYEG complex are found in eukaryotes and in archaea, where the subunit is known as Sec61α. Secretion of some proteins carrying a signal-peptide across the inner membrane in Gram-negative bacteria occurs via the preprotein translocase pathway.
Protein complexA protein complex or multiprotein complex is a group of two or more associated polypeptide chains. Protein complexes are distinct from multidomain enzymes, in which multiple catalytic domains are found in a single polypeptide chain. Protein complexes are a form of quaternary structure.Proteins in a protein complex are linked by non-covalentprotein–protein interactions. These complexes are a cornerstone of many (if not most) biological processes.
ArchaeaDomain of organismsExcluded(but cladistically included)EukaryotaSynonyms"Archaebacteria" Woese & Fox 1977"Archaeobacteria" Murray 1988"Mendocutes" Gibbons & Murray 1978"Mendosicutes" Murray 1984"Metabacteria" Hori and Osawa 1979"Neomura" Cavalier-Smith 2002"Archaebiota" Luketa 2012"Arkarya" Forterre 2015Archaea ( ) is a domain of organisms.
Amino acidOrganic compounds containing amine and carboxylic groupsStructure of a typical L-alpha-amino acid in the "neutral" formAmino acids are organic compounds that contain both amino and carboxylic acidfunctional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life.
Endoplasmic reticulumThe endoplasmic reticulum (ER) is a part of a transportation system of the eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for "little net". It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER).
PeptidePeptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Amino acids comprise peptides as residues.
Two-empire systemThe two-empire system (two-superkingdom system) was the top-level biological classification system in general use from the early 20th century until the establishment of the three-domain system (which itself is currently being challenged by the two-domain system). It classified cellular life into Prokaryota and Eukaryota as either "empires" or "superkingdoms".
Cryo-electron microscopyCryogenic electron microscopy (cryo-EM) is a transmission electron microscopy technique applied to samples cooled to cryogenic temperatures. Developed in the 1970s, advances in detector technology and software allow biomolecular structures to be imaged at near-atomic resolution. The approach has become a popular alternative to X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy in structural biology.*As an Amazon Associate I earn from qualifying purchases.