Flagellin

Flagellin

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.

tructure

The structure of flagellin is responsible for the helical shape of the flagellar filament, which is important for its proper function.

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.

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.

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).

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.

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

External links

*

More detailed information:Research article: bacterial flagellin and plant disease resistance, published by Zipfel. et al (2004) [http://www.nature.com/nature/journal/v428/n6984/abs/nature02485.html;jsessionid=8692DD78E661E5128B49702532117D6E ) Abstract Article]


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Look at other dictionaries:

  • flagellin — flagellin. См. флагеллин. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • flagellin — [flə jel′in, flə jel′ən] n. the protein that forms the flagella of bacteria * * * fla·gel·lin (flə jĕlʹĭn) n. The chief protein component of bacterial flagella. * * * …   Universalium

  • flagellin — [flə jel′in, flə jel′ən] n. the protein that forms the flagella of bacteria …   English World dictionary

  • flagellin — Any member of a class of proteins containing the amino acid, ε N methyllysine; this class represents the main protein component of the flagella of bacteria. * * * fla·gel·lin flə jel ən n a polymeric protein that is the chief …   Medical dictionary

  • flagellin — noun Etymology: flagellum + 1 in Date: 1955 a polymeric protein that is the chief constituent of bacterial flagella and that determines the specificity of the flagellum in eliciting an immune response …   New Collegiate Dictionary

  • flagellin — (flaj ē lin) The protein used to construct the filament of a bacterial flagellum …   Dictionary of microbiology

  • flagellin — Subunit protein (40 kD) of the bacterial flagellum …   Dictionary of molecular biology

  • flagellin — noun The main protein in the flagella of bacteria …   Wiktionary

  • Flagellin — Fla|gel|lin [lat. flagellum = Geißel, Peitsche; ↑ in (3)], das; s, e: aus Bakteriengeißeln isolierte Glykoproteine …   Universal-Lexikon

  • Flagellin — Flagelli̱n [zu ↑Flagelle] s; s, e: antigenes Protein der ↑Flagelle (1) …   Das Wörterbuch medizinischer Fachausdrücke

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