2BW4

Atomic Resolution Structure of Resting State of the Achromobacter cycloclastes Cu Nitrite Reductase

Summary for 2BW4

• Entry DOI: 10.2210/pdb2bw4/pdb
• Related: 1KCB 1NIA 1NIB 1NIC 1NID 1NIE 1NIF 1RZP 1RZQ 2BW5 2NRD
• Descriptor: COPPER-CONTAINING NITRITE REDUCTASE, COPPER (II) ION, MALONATE ION, ... (6 entities in total)
• Functional Keywords: oxidoreductase, denitrification, catalysis, enzyme mechanism, nitrate assimilation
• Biological source: ACHROMOBACTER CYCLOCLASTES
• Cellular location: Periplasm: P25006
• Total number of polymer chains: 1
• Total formula weight: 37717.25

Authors

Antonyuk, S.V.,Strange, R.W.,Sawers, G.,Eady, R.R.,Hasnain, S.S. (deposition date: 2005-07-12, release date: 2005-08-17, Last modification date: 2023-12-13)

Primary citation

Antonyuk, S.V.,Strange, R.W.,Sawers, G.,Eady, R.R.,Hasnain, S.S.
Atomic Resolution Structures of Resting-State, Substrate- and Product-Complexed Cu-Nitrite Reductase Provide Insight Into Catalytic Mechanism
Proc.Natl.Acad.Sci.USA, 102:12041-, 2005

PubMed Abstract: Copper-containing nitrite reductases catalyze the reduction of nitrite to nitric oxide (NO), a key step in denitrification that results in the loss of terrestrial nitrogen to the atmosphere. They are found in a wide variety of denitrifying bacteria and fungi of different physiology from a range of soil and aquatic ecosystems. Structural analysis of potential intermediates in the catalytic cycle is an important goal in understanding enzyme mechanism. Using "crystal harvesting" and substrate-soaking techniques, we have determined atomic resolution structures of four forms of the green Cu-nitrite reductase, from the soil bacterium Achromobacter cycloclastes. These structures are the resting state of the enzyme at 0.9 A, two species exhibiting different conformations of nitrite bound at the catalytic type 2 Cu, one of which is stable and also has NO present, at 1.10 A and 1.15 A, and a stable form with the product NO bound side-on to the catalytic type 2 Cu, at 1.12 A resolution. These structures provide incisive insights into the initial binding of substrate, its repositioning before catalysis, bond breakage (O-NO), and the formation of a stable NO adduct.

PubMed: 16093314
DOI: 10.1073/PNAS.0504207102

Experimental method

X-RAY DIFFRACTION (0.9 Å)