|PROSITE documentation PDOC60011|
Plants normally grow on substrates that are extremely rich in microorganisms, but infection remains a rare event. During evolution, plants have developed a variety of defense systems to protect themselves from potential pathogens. Proteins including thionins, plant defensins and chitinases have been shown to play active roles against pathogen infections. Plants produce a wide array of antimicrobial compounds for escaping from microorganisms by producing some proteins, which are having antibacterial, antifungal activity, etc. Antimicrobial peptides extracted from plants inhibit the growth of a variety of fungi, oomycetes, Gram-positive bacterial phytopathogenes and Saccharomyces cerevisiae. Many antimicrobial peptides (AMPs) which contain cysteine residues abundantly have been isolated from plants, and these are classified into the plant defensin family. Plant defensins can be classified broadly into three types (hevein type, C6 type, and C8 type) according to the number and the position of cysteine residues in the molecules. The C6 type of plant defensins are highly basic proteins that contains 6 cysteine residues and a continuous sequence of cysteine (-CC-). All the 6 cysteines are involved in disulfide bond formation for stabilizing protein tertiary structure [1,2,3,4].
+----------+ | | CxxxxCxxxxCCxxxCxxxxxxC | | | | +----|----+ | +-----------+
'C': conserved cysteine involved in a disulfide bond.
The overall tertiary structure of Ac-AMP2 consists of a centrally located, twisted anti-parallel β-sheet, which acts as the core of the protein and is more or less covered by the rest of the protein (see <PDB:1MMC>) .
Some C6 type AMPs are listed below:
Our signature pattern for plant C6 type antimicrobial peptides contains the six conserved cysteines involved in disulfide bonds with knottin scaffold [E1].Expert(s) to contact by email:
October 2006 / Pattern revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Cammue B.P.A. De Bolle M.F.C. Terras F.R.G. Proost P. Van Damme J. Rees S.B. Vanderleyden J. Broekaert W.F.|
|Title||Isolation and characterization of a novel class of plant antimicrobial peptides form Mirabilis jalapa L. seeds.|
|Source||J. Biol. Chem. 267:2228-2233(1992).|
|2||Authors||Liu Y. Luo J. Xu C. Ren F. Peng C. Wu G. Zhao J.|
|Title||Purification, characterization, and molecular cloning of the gene of a seed-specific antimicrobial protein from pokeweed.|
|Source||Plant Physiol. 122:1015-1024(2000).|
|3||Authors||Fujimura M. Ideguchi M. Minami Y. Watanabe K. Tadera K.|
|Title||Purification, characterization, and sequencing of novel antimicrobial peptides, Tu-AMP 1 and Tu-AMP 2, from bulbs of tulip (Tulipa gesneriana L.).|
|Source||Biosci. Biotechnol. Biochem. 68:571-577(2004).|
|4||Authors||Martins J.C. Maes D. Loris R. Pepermans H.A.M. Wyns L. Willem R. Verheyden P.|
|Title||H NMR study of the solution structure of Ac-AMP2, a sugar binding antimicrobial protein isolated from Amaranthus caudatus.|
|Source||J. Mol. Biol. 258:322-333(1996).|
|5||Authors||Tailor R.H. Acland D.P. Attenborough S. Cammue B.P.A. Evans I.J. Osborn R.W. Ray J.A. Rees S.B. Broekaert W.F.|
|Title||A novel family of small cysteine-rich antimicrobial peptides from seed of Impatiens balsamina is derived from a single precursor protein.|
|Source||J. Biol. Chem. 272:24480-24487(1997).|