3WFX

Crystal Structure of the Imidazole-Bound Form of the HGbRL's Globin Domain

Summary for 3WFX

• Entry DOI: 10.2210/pdb3wfx/pdb
• Related: 3WFW
• Descriptor: Hemoglobin-like flavoprotein fused to Roadblock/LC7 domain, PROTOPORPHYRIN IX CONTAINING FE, HEXANE-1,6-DIOL, ... (5 entities in total)
• Functional Keywords: globin, signalling, imidazole, oxygen transport
• Biological source: Methylacidiphilum infernorum
• Total number of polymer chains: 2
• Total formula weight: 35204.86

Authors

Teh, A.H. (deposition date: 2013-07-24, release date: 2014-08-06, Last modification date: 2023-11-08)

Primary citation

Teh, A.H.,Saito, J.A.,Najimudin, N.,Alam, M.
Open and Lys-His Hexacoordinated Closed Structures of a Globin with Swapped Proximal and Distal Sites.
Sci Rep, 5:11407-11407, 2015

PubMed Abstract: 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 subunit and helices F-H, the proximal site, from another. The open structure possesses a large cavity binding an imidazole molecule, while the closed structure forms a unique Lys-His hexacoordinated species, with the first turn of helix E unravelling to allow Lys52(E10) to bind to the haem. Ligand binding induces reorganization of loop CE, which is stabilized in the closed form, and helix E, triggering a large conformational movement in the open form. These provide a mechanical insight into how a signal may be relayed between the globin domain and the C-terminal domain of HGbRL, a Roadblock/LC7 domain. Comparison with HGbI, a closely related globin, further underlines the high degree of structural versatility that the globin fold is capable of, enabling it to perform a diversity of functions.

PubMed: 26094577
DOI: 10.1038/srep11407

Experimental method

X-RAY DIFFRACTION (1.94 Å)