RRC ID 48433
著者 Hattori T, Shiba H, Ashiki K, Araki T, Nagashima YK, Yoshimatsu K, Fujiwara T.
タイトル Anaerobic Growth of Haloarchaeon Haloferax volcanii by Denitrification Is Controlled by the Transcription Regulator NarO.
ジャーナル J Bacteriol
Abstract UNLABELLED:The extremely halophilic archaeon Haloferax volcanii grows anaerobically by denitrification. A putative DNA-binding protein, NarO, is encoded upstream of the respiratory nitrate reductase gene of H. volcanii. Disruption of the narO gene resulted in a loss of denitrifying growth of H. volcanii, and the expression of the recombinant NarO recovered the denitrification capacity. A novel CXnCXCX7C motif showing no remarkable similarities with known sequences was conserved in the N terminus of the NarO homologous proteins found in the haloarchaea. Restoration of the denitrifying growth was not achieved by expression of any mutant NarO in which any one of the four conserved cysteines was individually replaced by serine. A promoter assay experiment indicated that the narO gene was usually transcribed, regardless of whether it was cultivated under aerobic or anaerobic conditions. Transcription of the genes encoding the denitrifying enzymes nitrate reductase and nitrite reductase was activated under anaerobic conditions. A putative cis element was identified in the promoter sequence of haloarchaeal denitrifying genes. These results demonstrated a significant effect of NarO, probably due to its oxygen-sensing function, on the transcriptional activation of haloarchaeal denitrifying genes.
IMPORTANCE:H. volcanii is an extremely halophilic archaeon capable of anaerobic growth by denitrification. The regulatory mechanism of denitrification has been well understood in bacteria but remains unknown in archaea. In this work, we show that the helix-turn-helix (HTH)-type regulator NarO activates transcription of the denitrifying genes of H. volcanii under anaerobic conditions. A novel cysteine-rich motif, which is critical for transcriptional regulation, is present in NarO. A putative cis element was also identified in the promoter sequence of the haloarchaeal denitrifying genes.
巻・号 198(7)
ページ 1077-86
公開日 2016-1-19
DOI 10.1128/JB.00833-15
PII JB.00833-15
PMID 26787768
PMC PMC4800875
MeSH Amino Acid Sequence Anaerobiosis Archaeal Proteins / genetics Archaeal Proteins / metabolism* Denitrification / physiology Gene Expression Regulation, Archaeal / physiology* Gene Expression Regulation, Enzymologic / physiology Haloferax volcanii / physiology* Molecular Sequence Data Nitrate Reductase / genetics Nitrate Reductase / metabolism Plasmids Promoter Regions, Genetic Transcription Factors / genetics Transcription Factors / metabolism* Transcription, Genetic
IF 3.006
引用数 12
WOS 分野 MICROBIOLOGY
リソース情報
一般微生物 JCM 9276 JCM 8864