Pilin

A Pilin is a Protein component of bacterial adhesive appendages that help the Bacterium to stick to Tissue Or Container Surfaces, often the Glycoproteins on the surface of Eukaryotic Cells.

• Context:
  • Pilins are post-translationally modified by Glycosylation Or Phosphorylation.
• Example(s):
  • Pseudomonas Aeruginosa http://www.uniprot.org/uniprot/P02973
  • PMID 2447019: “The polar pili of Pseudomonas aeruginosa consist of a subunit protein, pilin, which is a 144-residue polypeptide that contains a hydrophobic N-terminal region and eight hydrophilic regions distributed throughout the remainder of the molecule.”
• See: Bacteria.

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References

• (Wikipedia, 2009) ⇒ http://en.wikipedia.org/wiki/Pilin
  • Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. Bacterial pili are used in the exchange of genetic material during bacterial conjugation, and a short pilus called a fimbrium is used 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 pilin[1].
  • Pilin proteins themselves are α+β proteins characterized by a very long N-terminal alpha helix. Many pilins are post-translationally modified by glycosylation or phosphorylation. The assembly of a complete pilus 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[2]. The exact mechanism of pilus assembly from monomers is not known, although chaperone proteins have been identified for some types of pili[3] and specific amino acids required for proper pilus formation have been isolated[4].
• Gene Ontology http://amigo.geneontology.org/cgi-bin/amigo/term-details.cgi?term=GO:0009367&session_id=4594amigo1245235139
  • Accession: GO:0009367
  • Ontology: cellular component
  • Synonyms :None
  • Definition
    • An enzyme complex that catalyzes the cleavage of 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. [source: EC:3.4.23.43]----