Expression of the iron-responsive irpA gene from the cyanobacterium Synechococcus sp. strain PCC 7942

Document Type

Article

Publication Date

1-1-2003

Publication Title

Archives of Microbiology

Volume

179

Issue

2

First Page

131

Keywords

Bioreporter, Cyanobacteria, Iron deficiency, Promoter fusions, Synechococcus

Last Page

134

Abstract

Expression of the iron-stress-induced irpA gene of Synechococcus sp. strain PCC 7942 was investigated by constructing luminescent pirpA::luxAB promoter fusions. Growth of Fe-replete and Fe-limited cultures yielded high levels of luminescence only under conditions of iron deficiency. Promoter fusion deletions revealed that low Fe irpA transcription is dependent on a 25-nucleotide sequence that includes a region of dyad symmetry centered 19 nucleotides from the transcription start. Assaying luminescence at defined iron concentrations in trace-metal-buffered media showed that irpA transcription is activated at concentrations below 100 nm Fe. Overall, the expression pattern and promoter structure of irpA suggests a novel form of metal-dependent regulation in this species.

DOI

10.1007/s00203-002-0503-6

ISSN

03028933

PubMed ID

12560991

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