Structure-function analysis of decay-accelerating factor: identification of residues important for binding of the Escherichia coli Dr adhesin and complement regulation.

ABSTRACT: Decay-accelerating factor (DAF), a complement regulatory protein, also serves as a receptor for Dr adhesin-bearing Escherichia coli. The repeat three of DAF was shown to be important in Dr adhesin binding and complement regulation. However, Dr adhesins do not bind to red blood cells with the rare polymorphism of DAF, designated Dr(a(-)); these cells contain a point mutation (Ser165-Leu) in DAF repeat three. In addition, monoclonal antibody IH4 specific against repeat three was shown to block both Dr adhesin binding and complement regulatory functions of DAF. Therefore, to identify residues important in binding of Dr adhesin and IH4 and in regulating complement, we mutated 11 amino acids-predominantly those in close proximity to Ser165 to alanine-and expressed these mutations in Chinese ham

SUBMITTER: Hasan RJ 

PROVIDER: S-EPMC128121 | biostudies-literature | 2002 Aug

REPOSITORIES: biostudies-literature