PDBsum entry 4n4l

Oxidoreductase

PDB id: 4n4l

Contents

Protein chain

497 a.a.

Ligands

PO4 ×4

EDO ×7

HZN

HEC ×8

HG1

Waters ×417

PDB id:

4n4l

Name:

Oxidoreductase

Title:

Kuenenia stuttgartiensis hydroxylamine oxidoreductase soaked in hydrazine

Structure:

Hydroxylamine oxidoreductase. Chain: a. Synonym: similar to hydroxylamine oxidoreductase hao. Ec: 1.7.3.4

Source:

Candidatus kuenenia stuttgartiensis. Organism_taxid: 174633

Resolution:

1.90Å R-factor: 0.149 R-free: 0.163

Authors:

W.J.Maalcke,A.Dietl,S.J.Marritt,J.N.Butt,M.S.M.Jetten,J.T.Keltjens, T.R.M.B.Barends,B.Kartal

Key ref:

W.J.Maalcke et al. (2014). Structural basis of biological NO generation by octaheme oxidoreductases. J Biol Chem, 289, 1228-1242. PubMed id: 24302732 DOI: 10.1074/jbc.M113.525147

Date:

08-Oct-13 Release date: 11-Dec-13

Protein chain

Q1PX48  (Q1PX48_KUEST) -  Hydroxylamine oxidoreductase from Kuenenia stuttgartiensis

Seq: 536 a.a.

Struc: 497 a.a.

Enzyme reactions

• Enzyme class: E.C.1.7.2.9 - hydroxylamine oxidase.
• Reaction: hydroxylamine + 3 Fe(III)-[cytochrome c] = nitric oxide + 3 Fe(II)- [cytochrome c] + 3 H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1074/jbc.M113.525147

J Biol Chem 289:1228-1242 (2014)

PubMed id: 24302732

Structural basis of biological NO generation by octaheme oxidoreductases.

W.J.Maalcke, A.Dietl, S.J.Marritt, J.N.Butt, M.S.Jetten, J.T.Keltjens, T.R.Barends, B.Kartal.

ABSTRACT

Nitric oxide is an important molecule in all domains of life with significant biological functions in both pro- and eukaryotes. Anaerobic ammonium-oxidizing (anammox) bacteria that contribute substantially to the release of fixed nitrogen into the atmosphere use the oxidizing power of NO to activate inert ammonium into hydrazine (N2H4). Here, we describe an enzyme from the anammox bacterium Kuenenia stuttgartiensis that uses a novel pathway to make NO from hydroxylamine. This new enzyme is related to octaheme hydroxylamine oxidoreductase, a key protein in aerobic ammonium-oxidizing bacteria. By a multiphasic approach including the determination of the crystal structure of the K. stuttgartiensis enzyme at 1.8 Å resolution and refinement and reassessment of the hydroxylamine oxidoreductase structure from Nitrosomonas europaea, both in the presence and absence of their substrates, we propose a model for NO formation by the K. stuttgartiensis enzyme. Our results expand the understanding of the functions that the widespread family of octaheme proteins have.