9C14

Structure of the CopC-like domain of YcnJ

Summary for 9C14

• Entry DOI: 10.2210/pdb9c14/pdb
• Descriptor: Copper transport protein YcnJ, SULFATE ION, TRIETHYLENE GLYCOL, ... (4 entities in total)
• Functional Keywords: copper import, copc, ycnj, extracellular domain, metal binding protein
• Biological source: Bacillus subtilis (strain 168)
• Total number of polymer chains: 1
• Total formula weight: 11265.49

Authors

de Oliveira Silva, Y.R.,Zheng, D.,Fisher, O.S. (deposition date: 2024-05-28, release date: 2025-08-06, Last modification date: 2025-08-20)

Primary citation

de Oliveira Silva, Y.R.,Barnes, G.,Zheng, D.,Zhitnitsky, D.,Geathers, S.J.,Peters, S.C.,Szalai, V.A.,Helmann, J.D.,Fisher, O.S.
Copper acquisition in Bacillus subtilis involves Cu(II) exchange between YcnI and YcnJ.
J.Biol.Chem., 301:110480-110480, 2025

PubMed Abstract: The transition metal copper is biologically essential across all three domains of life. Several copper-dependent proteins and enzymes produced by the Gram-positive bacterium Bacillus subtilis have been characterized. However, many questions remain about how copper is recognized and trafficked to metalate cuproproteins. The ycnKJI operon in B. subtilis encodes a suite of proteins implicated in copper uptake and regulation, including the copper-binding protein YcnI and the putative copper importer YcnJ. Here, we demonstrate that one of the extracellular domains within YcnJ (YcnJ) binds Cu(II) in 1:1 stoichiometry with high affinity using a histidine brace motif. Biochemical results reveal that YcnJ and YcnI can exchange Cu(II). Genetic studies reveal that loss of either YcnI or YcnJ, or mutation of the key residues required for Cu(II)-binding, leads to a growth defect under conditions of copper limitation. Together, these data suggest that the Cu(II)-binding sites in both YcnI and YcnJ may contribute to efficient import under Cu limited conditions. Our results support a model in which YcnI may sequester Cu(II) from YcnJ, serving a regulatory role to limit the amount of copper that enters the cytoplasm and allowing Cu(II) to be stored for later import on the outer face of the membrane. This transfer of Cu(II) between extracellular domains of membrane-bound proteins represents a potential new paradigm in bacterial copper usage.

PubMed: 40669668
DOI: 10.1016/j.jbc.2025.110480

Experimental method

X-RAY DIFFRACTION (1.6 Å)