Identification of Novel DNA-Binding proteins Using DNA-Affinity Chromatography/Pull Down

This units presents methods through which one may isolate and identify novel bacterial DNA-binding proteins. Briefly, the DNA sequence of interest is affixed to beads, and then incubated with bacterial cytoplasmic extract. Washes with buffers containing nonspecific DNA and low-salt concentrations will remove non-adhering and low-specificity DNAbinding proteins, while subsequent washes with higher salt concentrations will elute more specific DNA-binding proteins. Eluted proteins may then be identified by standard proteomic techniques.