Functional roles of the aromatic residues in the stabilization of the [Fe(4)S(4)] cluster in the Iro protein from Acidithiobacillus ferrooxidans

J Microbiol Biotechnol. 2010 Feb;20(2):294-300.

Abstract

The Iro protein is a member of HiPIP family with the [Fe(4)S(4)] cluster for electron transfer. Many reports proposed that the conserved aromatic residues might be responsible for the stability of the iron-sulfur cluster in HiPIP. In this study, Tyr10 was found to be a critical residue for the stability of the [Fe(4)S(4)] cluster according to site-directed mutagenesis results. Tyr10, Phe26 and Phe48 were essential for the stability of the [Fe(4)S(4)] cluster under acidic condition. Trp44 were not involved in the stability of the [Fe(4)S(4)] cluster. Molecular structure modeling for the mutant Tyr10 proteins revealed that the aromatic group of Tyr10 may form a hydrophobic barrier to protect the [Fe(4)S(4)] cluster from solvent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acidithiobacillus / chemistry*
  • Acidithiobacillus / genetics
  • Acidithiobacillus / metabolism
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Iron-Sulfur Proteins / chemistry*
  • Iron-Sulfur Proteins / genetics
  • Iron-Sulfur Proteins / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Oxidoreductases / chemistry*
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • Protein Stability
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Iron-Sulfur Proteins
  • Oxidoreductases
  • iron oxidase, Thiobacillus ferrooxidans