1R27

Crystal Structure of NarGH complex

Summary for 1R27

• Entry DOI: 10.2210/pdb1r27/pdb
• Descriptor: Respiratory nitrate reductase 1 alpha chain, Respiratory nitrate reductase 1 beta chain, MOLYBDENUM ATOM, ... (7 entities in total)
• Functional Keywords: beta barrel; x-ray crystallography, oxidoreductase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 403893.00

Authors

Jormakka, M.,Richardson, D.,Byrne, B.,Iwata, S. (deposition date: 2003-09-26, release date: 2004-02-17, Last modification date: 2024-02-14)

Primary citation

Jormakka, M.,Richardson, D.,Byrne, B.,Iwata, S.
Architecture of NarGH reveals a structural classification of Mo-bisMGD enzymes
Structure, 12:95-104, 2004

PubMed Abstract: The structure of the catalytic and electron-transfer subunits (NarGH) of the integral membrane protein, respiratory nitrate reductase (Nar) has been determined to 2.0 A resolution revealing the molecular architecture of this Mo-bisMGD (molybdopterin-guanine-dinucleotide) containing enzyme which includes a previously undetected FeS cluster. Nar, together with the related enzyme formate dehydrogenase (Fdh-N), is a key enzyme in the generation of proton motive force across the membrane in Escherichia coli nitrate respiration. A comparative study revealed that Nar and Fdh-N employ different approaches for acquiring substrate, reflecting different catalytic mechanisms. Nar uses a very narrow and nonpolar substrate-conducting cavity with a nonspecific substrate binding site, whereas Fdh-N accommodates a wider, positively charged substrate-conducting cavity with a more specific substrate binding site. The Nar structure also demonstrates the first example of an Asp side chain acting as a Mo ligand providing a structural basis for the classification of Mo-bisMGD enzymes.

PubMed: 14725769
DOI: 10.1016/j.str.2003.11.020

Experimental method

X-RAY DIFFRACTION (2 Å)