Characterization of the C-domain of the Escherichia coli transcriptional repressor NikR.
Contributors: University of Toronto.  Dept. of Chemistry.
Published: 2004
Language: eng
Number of pages: 38
Description: NikR is a 15 kDa protein that negatively regulates transcription of the  nikABCDE operon, which encodes for an ATP-dependent Ni(II) permease in Escherichia coli. The C-terminal domain of this protein contains the metal binding residues arranged in a novel square planar nickel binding site. In order to further characterize this metal binding activity the C-terminal domain of NikR containing residues 49--133 was cloned, expressed and purified. The metal selectivity of this fragment was then examined using electronic absorption spectroscopy and small molecule competitors.The affinity of the C-domain for metals parallels the Irving-William series of metal complex stabilities, Co(II) &lt; Ni(II) &lt; Cu(II) &ge; Zn(II), indicating that it does not display selectivity for Ni(II) over the other metals investigated. The characteristics of the C-domain are very similar to the previously characterized full-length protein indicating the DNA-binding N-terminal region does not have an effect on high affinity metal binding.
Notes: Adviser:  Deborah Zamble.

Thesis (M.Sc.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Masters Abstracts International, Volume: 43-03, page: 0847.

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