Fluorescence and Chemical Studies on the Interaction of Escherichia coli DNA-Binding Protein with Single-Stranded DNA†

Pradip K. Bandyopadhyay, Cheng Wen Wu*

*Corresponding author for this work

研究成果: Article

32 引文 斯高帕斯(Scopus)

摘要

Nanosecond and steady-state fluorescence spectroscopy were used to probe the environment of the tryptophan residues of Escherichia coli DNA-binding protein. A spectral shift and a change in quantum yield of the protein upon binding to DNA or oligonucleotides indicate that the tryptophan residues are near or at the DNA binding site. The observation of two excited-state lifetimes of the protein indicates that there is heterogeneity in the microenvironments of these tryptophan residues. The “short-lifetime” tryptophan residues are more sensitive to the interaction with DNA than the “long-lifetime” residues. The results of solute-perturbation studies with iodide or acrylamide indicate that there are tryptophan residues near the surface of the protein which are heterogeneous in their accessibility to these quenchers and that they become less accessible after DNA binding. Also, lysine residues of the protein have been shown to be essential to DNA binding by chemical-modification studies. Tyrosine, arginine, and cysteine residues appear not to be involved in this binding process. From studies of the decay of fluorescence anisotropy of the binding protein in the presence and absence of DNA, it has been concluded that (a) the tetrameric binding protein does not dissociate into subunits upon binding to the oligonucleotide d(pT)i6 and (b) the binding protein-fd DNA complex possesses “local flexibility” and, therefore, cannot be described as a continuous, rigid rod.

原文English
頁(從 - 到)4078-4085
頁數8
期刊Biochemistry
17
發行號19
DOIs
出版狀態Published - 1 一月 1978

指紋 深入研究「Fluorescence and Chemical Studies on the Interaction of Escherichia coli DNA-Binding Protein with Single-Stranded DNA†」主題。共同形成了獨特的指紋。

  • 引用此