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.
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 DeltatatC 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 c1 from the second A. ferrooxidans cytochrome bc1 complex. These findings underline the genotypic heterogeneity within the A. ferrooxidans species. The results suggest that Iro transfers electrons from a cytochrome bc1 complex to a terminal oxidase, as proposed for the HiPIP in photosynthetic bacteria.
Bruscella
Patrice
P
Laboratoire de Chimie Bactérienne, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Cassagnaud
Laure
L
Laboratoire de Chimie Bactérienne, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Ratouchniak
Jeanine
J
Laboratoire de Chimie Bactérienne, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Brasseur
Gaël
G
Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Lojou
Elisabeth
E
Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Amils
Ricardo
R
Universidad Autonoma de Madrid, Centro de Biologia Molecular, Cantoblanco, Madrid, Spain.
Bonnefoy
Violaine
V
Laboratoire de Chimie Bactérienne, IBSM, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
D042763:Acidithiobacillus / Q000145:classification / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D026901:Membrane Transport Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; C007943:high potential iron-sulfur protein; C408585:twin-arginine translocase complex, E coli; D010088:Oxidoreductases; C074859:iron oxidase, Thiobacillus ferrooxidans