Molecular Mechanism of Facilitated Dissociation of Fis Protein from DNA

• DOI: 10.1021/jacs.6b08416
• Publication Date: 2016-09-30T00:11:53Z
• Authors: Min-Yeh Tsai; Bin Zhang; Weihua Zheng; Peter G. Wolynes
• Keywords: Stoichiometry; Nucleoid; Ternary complex

Fis protein is a nucleoid-associated that plays many roles in transcriptional regulation and DNA site-specific recombination. In contrast to the naïve expectation based on stoichiometry, recent single-molecule studies have shown dissociation of from accelerated by increasing concentration protein. Because detailed molecular mechanism facilitated still not clear, this study, we employ computational methods explore binding landscapes Fis:DNA complexes with various stoichiometries. When two molecules are present, simulations uncover ternary complex, where originally bound partially dissociated DNA. The support three-state sequential kinetic model (N ⇄ I → D) for dissociation, thus explaining concentration-dependent dissociation.