External surface display of proteins linked to DNA-binding domains

A novel system (DBDX) was developed which allows the external surface displ ay on filamentous bacteriophage of proteins fused to either the N- or the C -terminus of a DNA-binding protein. In conjunction with helper phage infect ion, expression of proteins fused to the estrogen receptor DNA-binding doma in (DBD) in a phagemid vector containing the DNA sequence recognized by the DBD resulted in the production of phage particles which display the fusion protein through the phage pVIII coat on the external surface of the partic le. The viability of the technique was established with several model syste ms: particles displaying the C-terminal domain of N-cadherin or the biotiny lation domain of propionyl coenzyme A carboxylase fused to the C-terminus o f the DBD were found to be bound specifically by antibody or streptavidin, respectively. Human re constant region cDNA was selected from a N-terminal DBD fusion lymphocyte cDNA library after two rounds of selection with anti- re antibody. This display system may complement currently available bacteri al selection techniques. (C) 2001 academic Press.