AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Other Versions of this Article:
AEM.01978-06v1
73/4/1065    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Shimamura, M.
Right arrow Articles by Fujii, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shimamura, M.
Right arrow Articles by Fujii, T.
Agricola
Right arrow Articles by Shimamura, M.
Right arrow Articles by Fujii, T.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, February 2007, p. 1065-1072, Vol. 73, No. 4
0099-2240/07/$08.00+0     doi:10.1128/AEM.01978-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Isolation of a Multiheme Protein with Features of a Hydrazine-Oxidizing Enzyme from an Anaerobic Ammonium-Oxidizing Enrichment Culture{triangledown}

Munetaka Shimamura,1 Takashi Nishiyama,1 Hiroyuki Shigetomo,1 Takeshi Toyomoto,1 Yuka Kawahara,1 Kenji Furukawa,2 and Takao Fujii1*

Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan,1 Science and Technology, Kumamoto University Graduate School, 2-39-1 Kurokami, Kumamoto 860-8555, Japan2

Received 21 August 2006/ Accepted 4 December 2006

A multiheme protein having hydrazine-oxidizing activity was purified from enriched culture from a reactor in which an anammox bacterium, strain KSU-1, was dominant. The enzyme has oxidizing activity toward hydrazine but not hydroxylamine and is a 130-kDa homodimer composed of a 62-kDa polypeptide containing eight hemes. It was therefore named hydrazine-oxidizing enzyme (HZO). With cytochrome c as an electron acceptor, the Vmax and Km for hydrazine are 6.2 ± 0.3 µmol/min · mg and 5.5 ± 0.6 µM, respectively. Hydrazine (25 µM) induced an increase in the proportion of reduced form in the spectrum, whereas hydroxylamine (500 µM) did not. Two genes coding for HZO, hzoA and hzoB, were identified within the metagenomic DNA from the culture. The genes encode the same amino acid sequence except for two residues. The sequences deduced from these genes showed low-level identities (<30%) to those of all of the hydroxylamine oxidoreductases reported but are highly homologous to two hao genes found by sequencing the genome of "Candidatus Kuenenia stuttgartiensis" (88% and 89% identities). The purified enzyme might therefore be a novel hydrazine-oxidizing enzyme having a critical role in anaerobic ammonium oxidation.

* Corresponding author. Mailing address: Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan. Phone: 81-96-326-3948. Fax: 81-96-323-1331. E-mail: fujii{at}life.sojo-u.ac.jp.

{triangledown} Published ahead of print on 15 December 2006.

Applied and Environmental Microbiology, February 2007, p. 1065-1072, Vol. 73, No. 4
0099-2240/07/$08.00+0     doi:10.1128/AEM.01978-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2007 by the American Society for Microbiology. All rights reserved.