Structural organization of the gene encoding the human iron-sulfur subunit of succinate dehydrogenase

We have examined the expression of the gene encoding the iron-protein subunit (Ip) of succinate dehydrogenase in Saccharomyces cerevisiae. The gene had been cloned by us and shown to be subject to glucose regulation (A. Lombardo, K. Carine, and I. E. Scheffler, J. Biol. Chem. 265:10419-10423, 1990). We discovered that a significant part of the regulation of the Ip mRNA levels by glucose involves the regulation of the turnover rate of this mRNA. In the presence of glucose, the half-life appears to be less than 5 min, while in glycerol medium, the half-life is greater than 60 min. The gene is also regulated transcriptionally by glucose. The upstream promoter sequence appeared to have four regulatory elements with consensus sequences shown to be responsible for the interaction with the HAP2/3/4 regulatory complex. A deletion analysis has shown that the two distal elements are redundant. These measurements were carried out by Northern (RNA) analyses of Ip mRNA transcripts as well as by assays of beta-galactosidase activity in cells carrying constructs of the Ip promoter linked to the lacZ coding sequence. These observations on the regulation of mRNA stability were also extended to the mRNA of the flavoprotein subunit of succinate dehydrogenase and in some experiments of iso-1-cytochrome c.

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EPR and Electron Spin Echo Studies of Iron-Sulfur Clusters S-1 And S-2 in Bovine Heart Succinate Dehydrogenase

Advances in Membrane Biochemistry and Bioenergetics ◽

10.1007/978-1-4684-8640-7_43 ◽

1987 ◽

pp. 449-458 ◽

Cited By ~ 1

Author(s):

Russell LoBrutto ◽

Paul E. Haley ◽

Chang-An Yu ◽

Tomoko Ohnishi

Keyword(s):

Succinate Dehydrogenase ◽

Electron Spin ◽

Spin Echo ◽

Electron Spin Echo ◽

Iron Sulfur Clusters ◽

Bovine Heart ◽

Iron Sulfur

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The HiPIP from the acidophilic Acidithiobacillus ferrooxidans is correctly processed and translocated in Escherichia coli, in spite of the periplasm pH difference between these two micro-organisms

Microbiology ◽

10.1099/mic.0.27476-0 ◽

2005 ◽

Vol 151 (5) ◽

pp. 1421-1431 ◽

Cited By ~ 34

Author(s):

Patrice Bruscella ◽

Laure Cassagnaud ◽

Jeanine Ratouchniak ◽

Gaël Brasseur ◽

Elisabeth Lojou ◽

...

Keyword(s):

Escherichia Coli ◽

Acidithiobacillus Ferrooxidans ◽

Biochemical Properties ◽

Gene Encoding ◽

Iron Sulfur Cluster ◽

E Coli ◽

Iron Sulfur ◽

Sulfur Protein ◽

Tat System ◽

Micro Organisms

The gene encoding a putative high-potential iron–sulfur protein (HiPIP) from the strictly acidophilic and chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 33020 has been cloned and sequenced. This potential HiPIP was overproduced in the periplasm of the neutrophile and heterotroph Escherichia coli. As shown by optical and EPR spectra and by electrochemical studies, the recombinant protein has all the biochemical properties of a HiPIP, indicating that the iron–sulfur cluster was correctly inserted. Translocation of this protein in the periplasm of E. coli was not detected in a ΔtatC mutant, indicating that it is dependent on the Tat system. The genetic organization of the iro locus in strains ATCC 23270 and ATCC 33020 is different from that found in strains Fe-1 and BRGM. Indeed, in A. ferrooxidans ATCC 33020 and ATCC 23270 (the type strain), iro was not located downstream from purA but was instead downstream from petC2, encoding cytochrome c 1 from the second A. ferrooxidans cytochrome bc 1 complex. These findings underline the genotypic heterogeneity within the A. ferrooxidans species. The results suggest that Iro transfers electrons from a cytochrome bc 1 complex to a terminal oxidase, as proposed for the HiPIP in photosynthetic bacteria.

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