Cloning, molecular analysis and insertional mutagenesis of the bidirectional hydrogenase genes from the cyanobacterium Anacystis nidulans

FEBS Letters

Schmitz, Oliver²  Mikheeva, Lidia¹  Shestakov, Sergey¹  Boison, Gudrun²  Bothe, Hermann² 

[1] Department of Genetics, Moscow State University, Moscow 119899, Russian Federation;Botanisches Institut, Universität zu Köln, Gyrhofstr. 15, D-50923 Cologne, Germany

关键词: Hydrogenase;    Hydrogen metabolism;    Cyanobacterial mutant;    Nitrogen fixation;    Cyanobacteria;    Anacystis nidulans;   

DOI  :  10.1016/0014-5793(96)00936-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Among cyanobacteria, the heterocystous, N₂-fixing Anabaena variabilis and the unicellular Anacystis nidulans have recently been shown to possess an NAD⁺-dependent, bidirectional hydrogenase. A 5.0 kb DNA segment of the A. nidulans genome is now identified to harbor the structural genes hoxUYH coding for three subunits of the bidirectional hydrogenase. The gene arrangement in A. nidulans and in A. variabilis is remarkably dissimilar. In A. nidulans, but not in A. variabilis, the four accessory genes hoxW, hypA, hypB and hypF could be identified downstream of hoxH. An insertional homozygous mutant in hoxH from A. nidulans was completely inactive in performing Na₂S₂O₄-dependent H₂ evolution but could utilize the gas with almost 50% of the activity of the wild type. These findings with the first defined hydrogenase mutant in any photosynthetic, O₂-evolving microorganism indicate that the unicellular cyanobacterium A. nidulans possesses both an uptake and a bidirectional hydrogenase. The physiological role(s) of the two hydrogenases in unicellular non-N₂-fixing cyanobacteria is not yet understood.

【 授权许可】

Unknown