[Incorporation of Copper Ions into T2/T3 Centers of Two-Domain Laccases]

Mol Biol (Mosk). Jan-Feb 2018;52(1):29-35. doi: 10.7868/S0026898418010056.
[Article in Russian]

Abstract

Laccase belongs to the family of copper-containing oxidases. A study was made of the mechanism that sustains the incorporation of copper ions into the T2/T3 centers of recombinant two-domain laccase Streptomyces griseoflavus Ac-993. The occupancy of the T3 center by copper ions was found to increase with an increasing copper content in the culture medium and after dialysis of the protein preparation against a copper sulfate-containing buffer. The T2 center was filled only when overproducer strain cells were grown at a higher copper concentration in the medium. Two-domain laccases were assumed to possess a channel that serves to deliver copper ions to the T3 center during the formation of the three-dimensional laccase conformation and dialysis of the protein preparation. A narrower channel leads to the T2 center in two-domain laccases compared with three-domain ones, rendering the center less accessible for copper atoms. The incorporation of copper ions into the T2 center of two-domain laccases is likely to occur in the course of their biosynthesis or the formation of a functional trimer.

Keywords: Streptomyces griseoflavus; T2/T3 copper centers; X-ray structures; channels; two-domain laccases.

MeSH terms

  • Bacterial Proteins / chemistry*
  • Copper / chemistry*
  • Crystallography, X-Ray
  • Ions
  • Laccase / chemistry*
  • Streptomyces / chemistry*

Substances

  • Bacterial Proteins
  • Ions
  • Copper
  • Laccase