The 2.0-Å crystal structure of tachylectin 5A provides evidence for the common origin of the innate immunity and the blood coagulation systems

Norman Kairies, Hans Georg Beisel, Pablo Fuentes-Prior, Ryoko Tsuda, Tatsushi Muta, Sadaaki Iwanaga, Wolfram Bode, Robert Huber, Shun Ichiro Kawabata

Research output: Contribution to journalArticlepeer-review

112 Citations (Scopus)

Abstract

Because invertebrates lack an adaptive immune system, they had to evolve effective intrinsic defense strategies against a variety of microbial pathogens. This ancient form of host defense, the innate immunity, is present in all multicellular organisms including humans. The innate immune system of the Japanese horseshoe crab Tachypleus tridentatus, serving as a model organism, includes a hemolymph coagulation system, which participates both in defense against microbes and in hemostasis. Early work on the evolution of vertebrate fibrinogen suggested a common origin of the arthropod hemolymph coagulation and the vertebrate blood coagulation systems. However, this conjecture could not be verified by comparing the structures of coagulogen, the clotting protein of the horseshoe crab, and of mammalian fibrinogen. Here we report the crystal structure of tachylectin 5A (TL5A), a nonself-recognizing lectin from the hemolymph plasma of T. tridentatus. TLSA shares not only a common fold but also related functional sites with the γ fragment of mammalian fibrinogen. Our observations provide the first structural evidence of a common ancestor for the innate immunity and the blood coagulation systems.

Original languageEnglish
Pages (from-to)13519-13524
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume98
Issue number24
DOIs
Publication statusPublished - 2001 Nov 20

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'The 2.0-Å crystal structure of tachylectin 5A provides evidence for the common origin of the innate immunity and the blood coagulation systems'. Together they form a unique fingerprint.

Cite this