TI  - Structure of an extracellular <prot>gp130</prot> cytokine receptor signaling complex.
PG  - 2150-5
AB  - The activation of <prot>gp130</prot>, a shared signal-transducing receptor for a family
      of cytokines, is initiated by recognition of ligand followed by
      oligomerization into a higher order signaling complex. Kaposi's
      sarcoma-associated herpesvirus encodes a functional homolog of human
       <prot>interleukin-6</prot> (<prot>IL-6</prot>)  that activates  human <prot>gp130</prot> . In the 2.4 angstrom
      crystal structure of the extracellular signaling assembly between viral
      <prot>IL-6</prot> and human <prot>gp130</prot>, two complexes are cross-linked into a tetramer
      through direct interactions between the immunoglobulin domain of <prot>gp130</prot> and
      site III of viral <prot>IL-6</prot>, which is necessary for receptor activation. Unlike
      human <prot>IL-6</prot> (which uses many hydrophilic residues), the viral cytokine
      largely uses hydrophobic amino acids to contact <prot>gp130</prot>, which enhances the
      complementarity of the viral <prot>IL-6</prot>-<prot>gp130</prot> binding interfaces. The
      cross-reactivity of <prot>gp130</prot> is apparently due to a chemical plasticity
      evident in the amphipathic <prot>gp130</prot> cytokine-binding sites.
AD  - Department of Microbiology and Immunology, Stanford University School of
