CorA is a copper repressible surface-associated copper(I)-binding protein produced in Methylomicrobium album BG8.
CorA is a copper repressible protein previously identified in the methanotrophic bacterium Methylomicrobium album BG8. In this work, we demonstrate that CorA is located on the cell surface and binds one copper ion per protein molecule, which, based on X-ray Absorption Near Edge Structure analysis, is in the reduced state (Cu(I)). The structure of endogenously expressed CorA was solved using X-ray crystallography. The 1.6 Å three-dimensional structure confirmed the binding of copper and revealed that the copper atom was coordinated in a mononuclear binding site defined by two histidines, one water molecule, and the tryptophan metabolite, kynurenine. This arrangement of the copper-binding site is similar to that of its homologous protein MopE* from Metylococcus capsulatus Bath, confirming the importance of kynurenine for copper binding in these proteins. Our findings show that CorA has an overall fold similar to MopE, including the unique copper(I)-binding site and most of the secondary structure elements. We suggest that CorA plays a role in the M. album BG8 copper acquisition.
Norwegian Structural Biology Centre, Faculty of Science, University of Tromsø, Tromsø, Norway.
Kenneth A
KA
Johnson
Department of Molecular Biology, University of Bergen, Bergen, Norway.
Thomas
T
Ve
Department of Molecular Biology, University of Bergen, Bergen, Norway.
Oivind
O
Larsen
Department of Earth Science - Centre for Geobiology, University of Bergen, Bergen, Norway.
Rolf B
RB
Pedersen
Department of Molecular Biology, University of Bergen, Bergen, Norway.
Johan R
JR
Lillehaug
Department of Molecular Biology, University of Bergen, Bergen, Norway.
Harald B
HB
Jensen
Norwegian Structural Biology Centre, Faculty of Science, University of Tromsø, Tromsø, Norway.
Ronny
R
Helland
Department of Molecular Biology, University of Bergen, Bergen, Norway.
Odd A
OA
Karlsen
D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002942:Circular Dichroism; D003300:Copper / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D008772:Methylococcaceae / Q000502:physiology*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013499:Surface Properties
D001426:Bacterial Proteins; D002352:Carrier Proteins; D011994:Recombinant Proteins; D003300:Copper