Streptomyces coelicolor SCO4226 is a nickel binding protein

PLoS One. 2014 Oct 6;9(10):e109660. doi: 10.1371/journal.pone.0109660. eCollection 2014.

Abstract

The open reading frame SCO4226 of Streptomyces coelicolor A3(2) encodes an 82-residue hypothetical protein. Biochemical assays revealed that each SCO4226 dimer binds four nickel ions. To decipher the molecular function, we solved the crystal structures of SCO4226 in both apo- and nickel-bound (Ni-SCO4226) forms at 1.30 and 2.04 Å resolution, respectively. Each subunit of SCO4226 dimer adopts a canonical ferredoxin-like fold with five β-strands flanked by two α-helices. In the structure of Ni-SCO4226, four nickel ions are coordinated at the surface of the dimer. Further biochemical assays suggested that the binding of Ni2+ triggers the self-aggregation of SCO4226 in vitro. In addition, RT-qPCR assays demonstrated that the expression of SCO4226 gene in S. coelicolor is specifically up-regulated by the addition of Ni2+, but not other divalent ions such as Cu2+, Mn2+ or Co2+. All these results suggested that SCO4226 acts as a nickel binding protein, probably required for nickel sequestration and/or detoxification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Crystallography, X-Ray
  • Models, Molecular
  • Molecular Sequence Data
  • Nickel / metabolism*
  • Nickel / pharmacology
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Streptomyces coelicolor*
  • Up-Regulation / drug effects

Substances

  • Bacterial Proteins
  • Nickel

Grants and funding

This work was funded by the project 2012CB911000 from the Ministry of Science and Technology of China (http://www.most.gov.cn/) and the Program for Changjiang Scholars and Innovative Research Team in University (http://www.moe.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.