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Research article1997Peer reviewed

Shot-gun phage display mapping of two streptococcal cell-surface proteins

Jacobsson, Karin; Jonsson, Hans; Lindmark, Hans; Guss, Bengt; Lindberg, Martin; Frykberg, Lars


We have used a phage display shot-gun cloning technique to map the binding domains in two cell surface proteins from animal group C streptococci. The proteins, MAG and ZAG, have affinity for alpha(2)-macroglobulin (alpha(2)M), serum albumin and IgG. In this work, parts of the cloned i mag and zag genes were randomly cloned into a phagemid vector, and recombinant phages expressing alpha(2)-M- or albumin-binding activity were isolated through panning against immobilized alpha(2)M or albumin. Analysis of the clones revealed two distinct alpha(2)M-binding sites in protein MAG and two slightly overlapping binding sites in protein ZAG. The minimal albumin-binding domain in protein ZAG, as deduced from the affinity selected clones, consisted of 42 amino acids. These results show that the phage display shot-gun cloning is a rapid and convenient way to characterize the binding site(s) in receptor proteins without any prior knowledge of their number, size, and localization.


phage display shot gun cloning; Streptococcus dysgalatiae; Streptococcus zooepidemicus; alpha(2)-macroglobulin-binding; albumin-binding

Published in

Microbiological Research
1997, Volume: 152, number: 2, pages: 121-128