1M60

Solution Structure of Zinc-substituted cytochrome c

Summary for 1M60

• Entry DOI: 10.2210/pdb1m60/pdb
• NMR Information: BMRB: 5026
• Descriptor: Zinc-substituted cytochrome c, ZINC SUBSTITUTED HEME C (2 entities in total)
• Functional Keywords: six-coordinated zinc cyt c, electron transport
• Biological source: Equus caballus (horse)
• Cellular location: Mitochondrion matrix: P00004
• Total number of polymer chains: 1
• Total formula weight: 12353.67

Authors

Qian, C.,Yao, Y.,Tong, Y.,Wang, J.,Tang, W. (deposition date: 2002-07-11, release date: 2002-08-07, Last modification date: 2024-11-20)

Primary citation

Qian, C.,Yao, Y.,Tong, Y.,Wang, J.,Tang, W.
Structural analysis of zinc-substituted cytochrome c.
J.Biol.Inorg.Chem., 8:394-400, 2003

PubMed Abstract: Zinc-substituted cytochrome c has been widely used in studies of protein-protein interactions and photo-induced electron transfer reactions between proteins. However, the coordination geometry of zinc in zinc-substituted cyt c has not yet been determined; two different opinions about the coordination have been reached. Here the solution structures of zinc-substituted cytochrome c that might be five-coordinated and six-coordinated have been refined separately by using (1)H NMR spectroscopy, and the zinc coordination geometry was determined just by NOE distance constraints. Structural analysis of the energy-minimized average solution structures of both the pentacoordinated and hexacoordinated geometries indicate that that zinc in zinc-substituted cyt c should be bound to both His18 and Met80, which means that the zinc is six-coordinated. RMSD values of the family of 25 six-coordinated structures from the average structure are 0.66+/-0.13 A and 1.09+/-0.16 A for the backbone and all heavy atoms, respectively. A statistical analysis of the structure indicates its satisfactory quality. Comparison of the solution structure of the six-coordinated energy-minimized average structure of zinc-substituted cytochrome c with the solution structure of reduced cytochrome c reveals that for the overall folding the secondary structure elements are very close. The availability of the structure provides for a better understanding of the protein-protein complex and for electron transfer processes between Zn cyt c and other metalloproteins.

PubMed: 12761660
DOI: 10.1007/s00775-002-0428-1

Experimental method

SOLUTION NMR