High affinity iron acquisition in Rhizobium leguminosarum requires the cycHJKL operon and the feuPQ gene products, which belong to the family of two-component transcriptional regulators

Yeoman, K.H., Wexler, M., Johnston, Andy, Delgado, M.-J. and Downie, J.A. (1997) High affinity iron acquisition in Rhizobium leguminosarum requires the cycHJKL operon and the feuPQ gene products, which belong to the family of two-component transcriptional regulators. Microbiology, 143 (1). pp. 127-134. ISSN 1350-0872

Full text not available from this repository. (Request a copy)

Abstract

The cycHJKL operon of Rhizobium leguminosarum has previously been shown to be involved in the maturation of cytochrome c, possibly by its involvement in the covalent attachment of haem to the apoprotein. Mutations in the cycHJKL genes abolish symbiotic nitrogen fixation. Here, we show that eye mutants are pleiotropically defective. They have lost a high affinity iron acquisition system due to their failure to make or to export siderophores. They also accumulate protoporphyrin IX, the immediate precursor of haem. A model to account for these phenotypes is presented. Immediately upstream of cycH is a gene, lipA, which is predicted to encode an outer-membrane lipoprotein. Further upstream of lipA, there are two other genes, whose products are similar in sequence to the widespread family of two-component transcriptional regulators. These two genes, feuP and feuQ did not affect the transcription of lipA, or of the cycHJKL operon. However, a mutation in feuQ also led to the loss of the high affinity iron uptake system, although siderophores were still produced.

Item Type: Article
Uncontrolled Keywords: cytochrome c,iron acquisition,nitrogen fixation,rhizobium,siderophore
Faculty \ School: Faculty of Science > School of Biological Sciences
Related URLs:
Depositing User: Pure Connector
Date Deposited: 26 Nov 2013 12:34
Last Modified: 23 Sep 2020 23:36
URI: https://ueaeprints.uea.ac.uk/id/eprint/44540
DOI:

Actions (login required)

View Item View Item