Thionins

Pfam_box
Symbol = Thionin
Name = Plant thionin


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caption =
Pfam= PF00321
InterPro= IPR001010
SMART=
PROSITE = PDOC00244
SCOP = 1cnb
TCDB = 1.C.44
OPM family= 149
OPM protein= 2plh
PDB=PDB3|1wuwB:28-72 PDB3|1bhp :28-72 PDB3|2plh :17-61PDB3|1ed0A:27-72 PDB3|1okhB:27-72 PDB3|1jmpA:7-52PDB3|1orlA:7-52 PDB3|1jmnA:1-42 PDB3|1jxuA:1-46PDB3|1jxtA:1-46 PDB3|1jxyA:1-46 PDB3|1jxwA:1-46PDB3|1ccn :1-46 PDB3|1jxxA:1-46 PDB3|1ab1 :1-46PDB3|1cnr :1-46 PDB3|1ejgA:1-46 PDB3|1cbn :1-46PDB3|1cxrA:1-46 PDB3|1ccm :1-46 PDB3|1crn :1-46

Thionins are small, basic plant proteins, 45 to 50 amino acids in length, which include three or four conserved disulfide linkages. The proteins are toxic to animal cells, presumably attacking the cell membrane and rendering it permeable:this results in the inhibition of sugar uptake and allows potassium and phosphate ions, proteins, and nucleotides to leak from cellscite journal |author=Vernon LP, Evett GE, Zeikus RD, Gray WR |title=A toxic thionin from Pyrularia pubera: purification, properties, and amino acid sequence |journal=Arch. Biochem. Biophys. |volume=238
issue=1 |pages=18–29 |year=1985 |pmid=3985614 |doi=10.1016/0003-9861(85)90136-5] . Thionins are mainly found in seeds where they may act as a defence against consumption by animals. A barley ("Hordeum vulgare") leaf thionin that is highly toxic to plant pathogens and is involved in the mechanism of plant defence against microbial infections has also been identifiedcite journal |author=Apel K, Andresen I, Becker W, Schluter K, Burges J, Parthier B |title=The identification of leaf thionin as one of the main jasmonate-induced proteins of barley (Hordeum vulgare) |journal=Plant Mol. Biol. |volume=19 |issue=2 |pages=193–204 |year=1992 |pmid=1377959 |doi=10.1007/BF00027341] . The hydrophobic protein crambin from the Abyssinian kale ("Crambe abyssinica") is also a member of the thionin family.

Databases

A database for antimicrobial peptides, including thionins is available: PhytAMP (http://phytamp.pfba-lab.org) [cite journal |author=Hammami R, Ben Hamida J, Vergoten G, Fliss I, |title=PhytAMP: a database dadicated to plant antimicrobial peptides.|journal=Nucleic Acid Research |year=2008 |pmid=18836196 |doi=10.1093/nar/gkn655] .

References