Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
(a) Two different haem types found in biological systems. The structure of haem c includes covalent thioether linkages to the protein. (b) Binding of haem c via the C-X1-X2-CH-binding motif (providing the proximal axial histidine ligand) and with histidine as the distal axial ligand.
