4J6U

Crystal Structure of Tyrosinase from Bacillus megaterium N205A mutant

Summary for 4J6U

• Entry DOI: 10.2210/pdb4j6u/pdb
• Related: 3NM8 4J6T 4J6V
• Descriptor: Tyrosinase (2 entities in total)
• Functional Keywords: type 3 copper proteins, oxidoreductase
• Biological source: Bacillus megaterium
• Total number of polymer chains: 2
• Total formula weight: 70422.91

Authors

Kanteev, M.,Goldfeder, M.,Adir, N.,Fishman, A. (deposition date: 2013-02-12, release date: 2013-12-25, Last modification date: 2023-09-20)

Primary citation

Kanteev, M.,Goldfeder, M.,Chojnacki, M.,Adir, N.,Fishman, A.
The mechanism of copper uptake by tyrosinase from Bacillus megaterium.
J.Biol.Inorg.Chem., 18:895-903, 2013

PubMed Abstract: Tyrosinase belongs to the type 3 copper enzyme family, containing a dinuclear copper center, CuA and CuB. It is mainly responsible for melanin production in a wide range of organisms. Although copper ions are essential for the activity of tyrosinase, the mechanism of copper uptake is still unclear. We have recently determined the crystal structure of tyrosinase from Bacillus megaterium (TyrBm) and revealed that this enzyme has tighter binding of CuA in comparison with CuB. Investigating copper accumulation in TyrBm, we found that the presence of copper has a more significant effect on the diphenolase activity. By decreasing the concentration of copper, we increased the diphenolase to monophenolase activity ratio twofold. Using a rational design approach, we identified five variants having an impact on copper uptake. We have found that a major role of the highly conserved Asn205 residue is to stabilize the orientation of the His204 imidazole ring in the binding site, thereby promoting the correct coordination of CuB. Further investigation of these variants revealed that Phe197, Met61, and Met184, which are located at the entrance to the binding site, not only play a role in copper uptake, but are also important for enhancing the diphenolase activity. We propose a mechanism of copper accumulation by the enzyme as well as an approach to changing the selectivity of TyrBm towards L-dopa production.

PubMed: 24061559
DOI: 10.1007/s00775-013-1034-0

Experimental method

X-RAY DIFFRACTION (2.5 Å)