1dy0
MURINE ENDOSTATIN, CRYSTAL FORM II
OverviewOverview
Endostatin is a proteolytic fragment of collagen XVIII that potently inhibits angiogenesis and tumour growth. Human endostatin contains a zinc ion, bound near the N terminus, which was not observed in the original structure of mouse endostatin at pH 5. Controversial data exist on the role of this zinc ion in the anti-tumour activity. We report two new crystal structures of mouse endostatin at pH 8.5 with bound zinc. One crystal form shows a metal ion coordination similar to that in human endostatin (His132, His134, His142, Asp207), but the conformation of the N-terminal segment is different. In the other crystal form, Asp136 replaces His132 as a zinc ligand. Site-directed mutagenesis of zinc-binding residues demonstrates that both coordination geometries occur in solution. The large degree of structural heterogeneity of the zinc-binding site has implications for endostatin function. We conclude that zinc is likely to play a structural rather than a critical functional role in endostatin.
About this StructureAbout this Structure
1DY0 is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
ReferenceReference
Variable zinc coordination in endostatin., Hohenester E, Sasaki T, Mann K, Timpl R, J Mol Biol. 2000 Mar 17;297(1):1-6. PMID:10704302 Page seeded by OCA on Fri May 2 14:25:05 2008