Combining Gel Retardation and Footprinting to Determine Protein-DNA Interactions of Specific and/or Less Stable Complexes.
Bio Protoc 2020;
10:e3843. [PMID:
33659492 DOI:
10.21769/bioprotoc.3843]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/24/2020] [Accepted: 10/26/2020] [Indexed: 11/02/2022] Open
Abstract
DNA footprinting is a classic technique to investigate protein-DNA interactions. However, traditional footprinting protocols can be unsuccessful or difficult to interpret if the binding of the protein to the DNA is weak, the protein has a fast off-rate, or if several different protein-DNA complexes are formed. Our protocol differs from traditional footprinting protocols, because it provides a method to isolate the protein-DNA complex from a native gel after treatment with the footprinting agent, thus removing the bound DNA from the free DNA or other protein-DNA complexes. The DNA is then extracted from the isolated complex before electrophoresis on a sequencing gel to determine the footprinting pattern. This analysis provides a possible solution for those who have been unable to use traditional footprinting methods to determine protein-DNA contacts.
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