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Type IV Filament
The type IV filament superfamily (TFF) is a group of Pilin, fibrous protein structures that includes a set of cell projections with evolutionarily related membrane proteins. The TFF family seems to have originated in the last universal common ancestor, from where it diversified into archaella, type IV pili, type II secretion systems, and the Tad pilus, Tad pili. Complexes in the TFF superfamily are unified by the presence of the eponymous type IV pilin, an AAA+ ATPase, an integral (cytoplasmic) membrane (IM) platform, and (with the exception of MSH) a prepilin peptidase. References Bacteriology Protein complexes {{Membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilin
Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. These structures can be used for the exchange of genetic material, or as a cell adhesion mechanism. Although not all bacteria have pili or fimbriae, bacterial pathogens often use their fimbriae to attach to host cells. In Gram-negative bacteria, where pili are more common, individual pilin molecules are linked by noncovalent protein-protein interactions, while Gram-positive bacteria often have polymerized LPXTG pilin. Type IV pilin Type IV pilin proteins are α+β proteins characterized by a very long N-terminal alpha helix. The assembly of these pili relies on interactions between the N-terminal helices of the individual monomers. The pilus structure sequesters the helices in the center of the fiber lining a central pore, while antiparallel beta sheets occupy the exterior of the fiber. Role of ComP pilin in bacterial transformation Genetic transformation is the process by w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Protein
Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane and can either penetrate the membrane (transmembrane) or associate with one or the other side of a membrane ( integral monotopic). Peripheral membrane proteins are transiently associated with the cell membrane. Membrane proteins are common, and medically important—about a third of all human proteins are membrane proteins, and these are targets for more than half of all drugs. Nonetheless, compared to other classes of proteins, determining membrane protein structures remains a challenge in large part due to the difficulty in establishing experimental conditions that can preserve the correct conformation of the protein in isolation from its native environment. Function Membrane proteins perform a variety of functions vital to the sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Universal Common Ancestor
The last universal common ancestor (LUCA) is the most recent population from which all organisms now living on Earth share common descent—the most recent common ancestor of all current life on Earth. This includes all cellular organisms; the origins of viruses are unclear but they share the same genetic code. LUCA probably harboured a variety of viruses. The LUCA is not the first life on Earth, but rather the latest form ancestral to all existing life. While there is no specific fossil evidence of the LUCA, the detailed biochemical similarity of all current life confirms its existence. Its characteristics can be inferred from shared features of modern genomes. These genes describe a complex life form with many co-adapted features, including transcription and translation mechanisms to convert information from DNA to RNA to proteins. The LUCA probably lived in the high-temperature water of deep sea vents near ocean-floor magma flows around 4 billion years ago. Histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaella
The archaellum (; formerly archaeal flagellum) is a unique structure on the cell surface of many archaea, that allows for swimming motility. The archaellum consists of a rigid helical filament that is attached to the cell membrane by a molecular motor. This molecular motorcomposed of cytosolic, membrane, and pseudo-periplasmic proteinsis responsible for the assembly of the filament and, once assembled, for its rotation. The rotation of the filament propels archaeal cells in liquid medium, in a manner similar to the propeller of a boat. The bacterial analog of the archaellum is the flagellum, which is also responsible for their swimming motility and can also be compared to a rotating corkscrew. Although the movement of archaella and flagella is sometimes described as "whip-like", this is incorrect, as only cilia from Eukaryotes move in this manner. Indeed, even "flagellum" (word derived from Latin meaning "whip") is a misnomer, as bacterial flagella work are also propeller-like str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type IV Pili
A pilus (Latin for 'hair'; plural: ''pili'') is a hair-like appendage found on the surface of many bacteria and archaea. The terms ''pilus'' and '' fimbria'' (Latin for 'fringe'; plural: ''fimbriae'') can be used interchangeably, although some researchers reserve the term ''pilus'' for the appendage required for bacterial conjugation. All conjugative pili are primarily composed of pilin – fibrous proteins, which are oligomeric. Dozens of these structures can exist on the bacterial and archaeal surface. Some bacteria, viruses or bacteriophages attach to receptors on pili at the start of their reproductive cycle. Pili are antigenic. They are also fragile and constantly replaced, sometimes with pili of different composition, resulting in altered antigenicity. Specific host responses to old pili structures are not effective on the new structure. Recombination genes of pili code for variable (V) and constant (C) regions of the pili (similar to immunoglobulin diversity). As the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type II Secretion System
The type 2 secretion system (often referred to as the type II secretion system or by the initials T2SS) is a type of protein secretion machinery found in various species of Gram-negative bacteria, including many human pathogens such as ''Pseudomonas aeruginosa'' and ''Vibrio cholerae''. The type II secretion system is one of six protein secretory systems commonly found in Gram-negative bacteria, along with the type I, type III, and type IV secretion systems, as well as the chaperone/usher pathway, the autotransporter pathway/type V secretion system, and the type VI secretion system (some bacteria also utilize the type VII secretion system). Like these other systems, the type II secretion system enables the transport of cytoplasmic proteins across the lipid bilayers that make up the cell membranes of Gram-negative bacteria. Secretion of proteins and effector molecules out of the cell plays a critical role in signaling other cells and in the invasion and parasitism of host cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tad Pilus
Tad or TAD may refer to: Places * Tad, West Virginia, an unincorporated community * Tad City, Texas, a coastal unincorporated community located on Olsovsky Road (Suburb of Ganado) * Tad, Isfahan, a village in Isfahan Province, Iran * Tad, Markazi, a village in Markazi Province, Iran People and fictional characters * Tad (given name) Sports * Tadamon Sour SC, a Lebanese association football club TAD * TAD Disability Services, an Australian charity * Technical Audio Devices, a brand of speakers by Pioneer Corporation * Telephone answering device, alternate term for an Answering machine * Technology aware design, a project of IMEC, a Belgian electronics company * Tax-allocation district, alternate term for a tax increment financing area * ''The Anglican Digest'', a religious magazine in the United States * Temporary additional duty, a form of Temporary duty assignment in the US Navy and US Marines * Thoracic aortic dissection, breakdown of the aorta in the chest * Topolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilin
Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. These structures can be used for the exchange of genetic material, or as a cell adhesion mechanism. Although not all bacteria have pili or fimbriae, bacterial pathogens often use their fimbriae to attach to host cells. In Gram-negative bacteria, where pili are more common, individual pilin molecules are linked by noncovalent protein-protein interactions, while Gram-positive bacteria often have polymerized LPXTG pilin. Type IV pilin Type IV pilin proteins are α+β proteins characterized by a very long N-terminal alpha helix. The assembly of these pili relies on interactions between the N-terminal helices of the individual monomers. The pilus structure sequesters the helices in the center of the fiber lining a central pore, while antiparallel beta sheets occupy the exterior of the fiber. Role of ComP pilin in bacterial transformation Genetic transformation is the process by w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AAA+
AAA, Triple A, or Triple-A is a three-letter initialism or abbreviation which may refer to: Airports * Anaa Airport in French Polynesia (IATA airport code AAA) * Logan County Airport (Illinois) (FAA airport code AAA) Arts, entertainment, and media Gaming * AAA (video game industry) - a category of high budget video games *'' TripleA'', an open source wargame Music Groups and labels * AAA (band), a Japanese pop band * Against All Authority (''-AAA-''), an American ska-punk band * Acid Angel From Asia ''(AAA)'' the first sub-unit of K-pop girl group TripleS referred to as "AVA" * Triple A (musical group), a Dutch trance group Works * Song on ''City'' (Strapping Young Lad album) * ''A.A.A'' (EP), by Nigerian band A.A.A Other music * Triple A or Adult Alternative Songs, a record chart Other uses in arts, entertainment, and media * Adult album alternative, a radio format * AAA, the production code for the 1970 ''Doctor Who'' serial ''Spearhead from Space'' * (''Aces o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prepilin Peptidase
Prepilin peptidase () is an enzyme found in Type IV filament systems responsible for the maturation of the pilin. This enzyme catalyses the following chemical reaction : Typically cleaves a -Gly-Phe- bond to release an N-terminal, basic peptide of 5-8 residues from type IV prepilin, and then N-methylates the new N-terminal amino group, the methyl donor being ''S''-adenosyl-L-methionine. This enzyme is present on the surface of many species of bacteria. All known enzymes with this activity are of the MEROPS MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibitor ... family A24. References External links * MEROPS A24 {{Portal bar, Biology, border=no EC 3.4.23 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriology
Bacteriology is the branch and specialty of biology that studies the morphology, ecology, genetics and biochemistry of bacteria as well as many other aspects related to them. This subdivision of microbiology involves the identification, classification, and characterization of bacterial species. Because of the similarity of thinking and working with microorganisms other than bacteria, such as protozoa, fungi, and viruses, there has been a tendency for the field of bacteriology to extend as microbiology. The terms were formerly often used interchangeably. However, bacteriology can be classified as a distinct science. Overview Definition Bacteriology is the study of bacteria and their relation to medicine. Bacteriology evolved from physicians needing to apply the germ theory to address the concerns relating to disease spreading in hospitals the 19th century. Identification and characterizing of bacteria being associated to diseases led to advances in pathogenic bacteriology. K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
