Open and Lys–His Hexacoordinated Closed Structures of a Globin with Swapped Proximal and Distal Sites

Globins are haem-binding proteins with a conserved fold made up of α-helices and can possess diverse properties. A putative globin-coupled sensor from Methylacidiphilum infernorum , HGbRL, contains an N-terminal globin domain whose open and closed structures reveal an untypical dimeric architecture. Helices E and F fuse into an elongated helix, resulting in a novel site-swapped globin fold made up of helices A–E, hence the distal site, from one...