1AOC

JAPANESE HORSESHOE CRAB COAGULOGEN

Summary for 1AOC

• Entry DOI: 10.2210/pdb1aoc/pdb
• Descriptor: COAGULOGEN, SULFATE ION (3 entities in total)
• Functional Keywords: coagulation factor, clottable protein, cystine knot superfamily
• Biological source: Tachypleus tridentatus
• Total number of polymer chains: 2
• Total formula weight: 39579.02

Authors

Bergner, A.,Oganessyan, V.,Muta, T.,Iwanaga, S.,Typke, D.,Huber, R.,Bode, W. (deposition date: 1996-11-28, release date: 1997-04-21, Last modification date: 2024-10-23)

Primary citation

Bergner, A.,Oganessyan, V.,Muta, T.,Iwanaga, S.,Typke, D.,Huber, R.,Bode, W.
Crystal structure of a coagulogen, the clotting protein from horseshoe crab: a structural homologue of nerve growth factor.
EMBO J., 15:6789-6797, 1996

PubMed Abstract: The clotting cascade system of the horseshoe crab (Limulus) is involved in both haemostasis and host defence. The cascade results in the conversion of coagulogen, a soluble protein, into an insoluble coagulin gel. The clotting enzyme excises the fragment peptide C from coagulogen, giving rise to aggregation of the monomers. The crystal structure of coagulogen reveals an elongated molecule that embraces the helical peptide C fragment. Cleavage and removal of the peptide C would expose an extended hydrophobic cove, which could interact with the hydrophobic edge of a second molecule, leading to a polymeric fibre. The C-terminal half of the coagulogen molecule exhibits a striking topological similarity to the neurotrophin nerve growth factor (NGF), providing the first evidence for a neurotrophin fold in invertebrates. Similarities between coagulogen and Spatzle, the Drosophila ligand of the receptor Toll, suggest that the neurotrophin fold might be considered more ancient and widespread than previously realized.

PubMed: 9003754

Experimental method

X-RAY DIFFRACTION (2 Å)