Open AccessRemodeling a DNA-binding protein as a specific in vivo inhibitor of bacterial secretin PulD
Author(s) -
Barbara Mouratou,
Francis Schaeffer,
Ingrid Guilvout,
Diana Tello-Manigne,
Anthony P. Pugsley,
Pedro M. Alzari,
Frédéric Pecorari
Publication year - 2007
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0702963104
Subject(s) - periplasmic space , biochemistry , escherichia coli , function (biology) , biology , secretion , chemistry , microbiology and biotechnology , gene
We engineered a class of proteins that binds selected polypeptides with high specificity and affinity. Use of the protein scaffold of Sac7d, belonging to a protein family that binds various ligands, overcomes limitations inherent in the use of antibodies as intracellular inhibitors: it lacks disulfide bridges, is small and stable, and can be produced in large amounts. Anin vitro combinatorial/selection approach generated specific, high-affinity (up to 140 pM) binders against bacterial outer membrane secretin PulD. When exported to theEscherichia coli periplasm, they inhibited PulD oligomerization, thereby blocking the type II secretion pathway of which PulD is part. Thus, high-affinity inhibitors of protein function can be derived from Sac7d and can be exported to, and function in, a cell compartment other than that in which they are produced.