PROSITE documentation PDOC60015
Mu-agatoxin family signature


Spider mu-agatoxins are cysteine-rich insecticidal polypeptides, which cause gradual but irreversible paralysis. These toxins cause repetitive firing and massive transmitter release (which is mediated by glutamate receptors) from presynaptic stores at neuromuscular junctions [1].

The mu-agatoxin family contains:

  • Mu-agatoxin 1-6 from Agelenopsis aperta (Funnel-web spider),
  • Curtatoxin 1-3 from Hololena curta (Funnel-web spider),
  • Delta-palutoxin IT1, IT2, IT3 and IT4 from Paracoelotes luctuosus (Spider),
  • Toxin ACTX-Hi:OB4219 from Hadronyche infensa (Fraser island funnel-web spider).

Mu-agatoxin family proteins have a [C-C-CC-C-C-C-C] cysteine arrangement. The three dimensional structure of mu-agatoxins possesses a knottin scafold (see <PDOC60004>) [E1] with a fourth pair of cysteine residues (marked '#' in the following schematic representation) involved in a vicinal disulfide linkage.

                              |             | #     #
                       |              ||      |     | |
                       +---------------+      +-----+ |
'C': conserved cysteine involved in a disulfide bond.
'#': fourth pair of cysteine residues.

Our signature pattern for mu-agatoxins contains the eight conserved cysteines involved in disulfide bonds.

Expert(s) to contact by email:

Ramakumar S.

Last update:

June 2005 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

MU_AGATOXIN, PS60015; Mu-agatoxin family signature  (PATTERN)


1AuthorsSkinner W.S. Adams M.E. Quistad G.B. Kataoka H. Cesarin B.J. Enderlin F.E. Schooley D.A.
TitlePurification and characterization of two classes of neurotoxins from the funnel web spider, Agelenopsis aperta.
SourceJ. Biol. Chem. 264:2150-2155(1989).
PubMed ID2914898


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