Editor: Annick Wilmotte
Cyanobacterial hydrogenases: diversity, regulation and applications
Article first published online: 28 SEP 2007
FEMS Microbiology Reviews
Volume 31, Issue 6, pages 692–720, November 2007
How to Cite
Tamagnini, P., Leitão, E., Oliveira, P., Ferreira, D., Pinto, F., Harris, D. J., Heidorn, T. and Lindblad, P. (2007), Cyanobacterial hydrogenases: diversity, regulation and applications. FEMS Microbiology Reviews, 31: 692–720. doi: 10.1111/j.1574-6976.2007.00085.x
- Issue published online: 28 SEP 2007
- Article first published online: 28 SEP 2007
- Received 5 January 2007; revised 12 July 2007; accepted 9 August 2007.First published online October 2007.
- transcriptional regulator
Cyanobacteria may possess two distinct nickel-iron (NiFe)-hydrogenases: an uptake enzyme found in N2-fixing strains, and a bidirectional one present in both non-N2-fixing and N2-fixing strains. The uptake hydrogenase (encoded by hupSL) catalyzes the consumption of the H2 produced during N2 fixation, while the bidirectional enzyme (hoxEFUYH) probably plays a role in fermentation and/or acts as an electron valve during photosynthesis. hupSL constitute a transcriptional unit, and are essentially transcribed under N2-fixing conditions. The bidirectional hydrogenase consists of a hydrogenase and a diaphorase part, and the corresponding five hox genes are not always clustered or cotranscribed. The biosynthesis/maturation of NiFe-hydrogenases is highly complex, requiring several core proteins. In cyanobacteria, the genes that are thought to affect hydrogenases pleiotropically (hyp), as well as the genes presumably encoding the hydrogenase-specific endopeptidases (hupW and hoxW) have been identified and characterized. Furthermore, NtcA and LexA have been implicated in the transcriptional regulation of the uptake and the bidirectional enzyme respectively. Recently, the phylogenetic origin of cyanobacterial and algal hydrogenases was analyzed, and it was proposed that the current distribution in cyanobacteria reflects a differential loss of genes according to their ecological needs or constraints. In addition, the possibilities and challenges of cyanobacterial-based H2 production are addressed.