1nwv

From Proteopedia

Revision as of 11:02, 20 March 2008

SOLUTION STRUCTURE OF A FUNCTIONALLY ACTIVE COMPONENT OF DECAY ACCELERATING FACTOR

Overview

The second and third modules of human decay accelerating factor (DAF) are necessary and sufficient to accelerate decay of the classical pathway (CP) convertase of complement. No structure of a mammalian protein with decay-accelerating activity has been available to date. We therefore determined the solution structure of DAF modules 2 and 3 (DAF approximately 2,3). Structure-guided analysis of 24 mutants identified likely contact points between DAF and the CP convertase. Three (R96, R69, and a residue in the vicinity of L171) lie on DAF approximately 2,3's concave face. A fourth, consisting of K127 and nearby R100, is on the opposite face. Regions of module 3 remote from the semiflexible 2-3 interface seem not to be involved in binding to the CP convertase. DAF thus seems to occupy a groove on the CP convertase such that both faces of DAF close to the 2-3 junction (including a positively charged region that encircles the protein at this point) interact simultaneously. Alternative pathway convertase interactions with DAF require additional regions of CCP 3 lying away from the 2-3 interface, consistent with the established additional requirement of module 4 for alternative pathway regulation.

Disease

Known diseases associated with this structure: Blood group Cromer OMIM:[125240], Blood group, Knops system OMIM:[120620], CR1 deficiency OMIM:[120620], Malaria, severe, resistance to OMIM:[120620], SLE susceptibility OMIM:[120620]

About this Structure

1NWV is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Solution structure of a functionally active fragment of decay-accelerating factor., Uhrinova S, Lin F, Ball G, Bromek K, Uhrin D, Medof ME, Barlow PN, Proc Natl Acad Sci U S A. 2003 Apr 15;100(8):4718-23. Epub 2003 Apr 2. PMID:12672958

Page seeded by OCA on Thu Mar 20 13:02:47 2008