Metal binding and activity of the Helicobacter pylori  transcription factor NikR.
Contributors: University of Toronto.  Dept. of Chemistry.
Published: 2004
Language: eng
Number of pages: 50
Description: In Helicobacter pylori, the urease enzyme activity and expression are regulated by nickel. It is thought that nickel-dependant expression of urease is controlled by a protein homologous to the Escherichia coli NikR transcription factor which, is a nickel responsive repressor on the nik operon. In contrast, the Helicobacter Pylori NikR (HpNikR) activates transcription of the ure operon.Metal-binding experiments reveal that both NikR proteins bind divalent transition metal ions in a similar coordination sphere. In the presence of nickel, HpNikR binds the ureA promoter and the binding site was characterized by in vitro assays. The protein also binds to the nikR gene promoter sequence, which is very similar to the inverted repeat sequence of the E. coli nik  operon but both are very different from the ureA promoter. These results suggest that HpNikR binds one operator sequence when acting as an activator and another one when acting as a repressor.
Notes: Adviser:  D. 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: 0846.

MICR copy on microfiche (1 microfiche).