1 / 13

Nitrate Reductases: There s more than one way to skin a snake or reduce a nitrate

General Information. Nitrate reductases catalyze the reduction of nitrate:NO3- 2H 2e- -> NO2- H2OThree classes in eubacteriarespiratory membrane-bound (Nar)periplasmic (Nap)assimilatory cytoplasmic (Nas). Cofactors. Hemeselectron transfer to iron sulfur clustersIron-sulfur clusters[3

aric
Download Presentation

Nitrate Reductases: There s more than one way to skin a snake or reduce a nitrate

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. Nitrate Reductases: There’s more than one way to skin a snake (or reduce a nitrate) Brad Bullock February 1, 2007

    2. General Information Nitrate reductases catalyze the reduction of nitrate: NO3- + 2H+ + 2e- -> NO2- + H2O Three classes in eubacteria respiratory membrane-bound (Nar) periplasmic (Nap) assimilatory cytoplasmic (Nas)

    3. Cofactors Hemes electron transfer to iron sulfur clusters Iron-sulfur clusters [3Fe-4S]1+,0 and [4Fe-4S]2+,1+ electron transfer to molybdenum Molybdopterin guanine dinucleotide surrounded by highly conserved regions -site of reduction

    4. Membrane-bound Nitrate Reductase (Nar) Ubiquinol oxidation releases two protons into the periplasm and two electrons into the protein The ?-helices of the ? subunit (25 kDa) anchor the ? (140 kDa) and ? (60 kDa) subunits to the cytoplasmic membrane Active site is on molybdenum Electron transfer pathway of 90 Å Expression of nar genes is induced by presence of nitrate

    5. Membrane-bound Nitrate Reductase: 1Q16

More Related