Helicobacter pylori electron micrograph, showing multiple flagella on the cell surface

Flagellin is a protein that arranges itself in a hollow cylinder to form the filament in bacterial flagellum. It has a mass of about 30,000 to 60,000 daltons. Flagellin is the principal substituent of bacterial flagellum, and is present in large amounts on nearly all flagellated bacteria. Image File history File linksMetadata EMpylori. ... Image File history File linksMetadata EMpylori. ... Binomial name Helicobacter pylori ((Marshall 1985) Goodwin 1989) Helicobacter pylori is a helical shaped Gram-negative bacterium that colonises the mucus layer of gastric epithelium in the stomach, and also the duodenum when it has undergone gastric metaplasia. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... // A flagellum (plural: flagella) is a long, slender projection from the cell body, composed of microtubules and surrounded by the plasma membrane. ... The unified atomic mass unit (u), or Dalton (Da), is a small unit of mass used to express atomic and molecular masses. ... // A flagellum (plural: flagella) is a long, slender projection from the cell body, composed of microtubules and surrounded by the plasma membrane. ...

Structure

The structure of flagellin is responsible for the helical shape of the flagellar filament, which is important for its proper function. A helix (pl: helices), from the Greek word έλικας/έλιξ, is a twisted shape like a spring, screw or a spiral (correctly termed helical) staircase. ...

The N- and C-termini of flagellin form the inner core of the flagellin protein, and is responsible for flagellin's ability to polymerize into a filament. The central portion of the protein makes up the outer surface of the flagellar filament. While the termini of the protein is quite similar between all bacterial flagellins, the central portion is wildly variable. The N-terminal end refers to the extremity of a protein or polypeptide terminated by an amino acid with a free amine group (NH2). ... The C-terminal end refers to the extremity of a protein or polypeptide terminated by an amino acid with a free carboxyl group (COOH). ... A polymer (from Greek: πολυ, polu, many; and μέρος, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ...

Immune response

In mammals

Mammals often have acquired immune responses (T-cell and antibody responses) to flagellated bacterium occurs frequently to flagellar antigens. Some bacteria are able to switch between multiple flagellin genes in order to evade this response. Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange). ... T cells belong to a group of white blood cells known as lymphocytes and play a central role in cell-mediated immunity. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... For a non-technical introduction to the topic, see Introduction to Genetics. ...

The propensity of the immune response to flagellin may be explained by two facts:

• First, flagellin is an extremely abundant protein in flagellated bacteria.
• Secondly, there exists a specific innate immune receptor that recognizes flagellin, Toll-like receptor 5 (TLR5).

A immune receptor (or immunologic receptor) is a receptor, usually on a cell membrane, which binds to a substance (for example, a cytokine) and causes a response in the immune system. ... Toll-like receptors (TLRs) are type I transmembrane proteins that serve as a key part of the innate immune system. ... TLR 5 is a toll-like receptor. ...

In plants

In addition a 22 amino acid sequence (flg22) of the conserved N-terminal part of flagellin is known to activate plant defence mechanisms. Flagellin perception in Arabidopsis thaliana functions via the receptor-like-kinase, FLS2 (flagellin-sensitive-2)). Mitogen-activated-protein-kinases (MAPK) acts as signalling compounds and more than 900 genes are affected upon flg22 treatment. Binomial name Arabidopsis thaliana (L.) Heynh. ... The mitogen-activated protein kinase (MAPK) pathway[1][2][3][4][5][6][7][8][9] Mitogen-activated protein (MAP) kinases (EC 2. ...

Pre-stimulation with a synthetic flg22-peptide led to enhanced resistance against bacterial invaders.

External links

• MeSH Flagellin

More detailed information: Research article: bacterial flagellin and plant disease resistance, published by Zipfel. et al (2004) ) Abstract Article Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ...