6M9A

Bordetella pertussis globin coupled sensor regulatory domain (BpeGReg)

Summary for 6M9A

• Entry DOI: 10.2210/pdb6m9a/pdb
• Descriptor: Signaling protein, PROTOPORPHYRIN IX CONTAINING FE, HYDROGEN PEROXIDE, ... (5 entities in total)
• Functional Keywords: globin, heme, sensor, bordetella, pertussis, iron, fe, coupled, signaling protein, bpeglobin, bpegreg
• Biological source: Bordetella pertussis
• Total number of polymer chains: 3
• Total formula weight: 59523.53

Authors

Rivera, S.R.,Hoffer, E.D.,Dunham, C.M.,Weinert, E.E. (deposition date: 2018-08-23, release date: 2018-11-14, Last modification date: 2023-10-11)

Primary citation

Rivera, S.,Young, P.G.,Hoffer, E.D.,Vansuch, G.E.,Metzler, C.L.,Dunham, C.M.,Weinert, E.E.
Structural Insights into Oxygen-Dependent Signal Transduction within Globin Coupled Sensors.
Inorg Chem, 57:14386-14395, 2018

PubMed Abstract: In order to respond to external stimuli, bacteria have evolved sensor proteins linking external signals to intracellular outputs that can then regulate downstream pathways and phenotypes. Globin coupled sensor proteins (GCSs) serve to link environmental O levels to cellular processes by coupling a heme-containing sensor globin domain to a catalytic output domain. However, the mechanism by which O binding activates these proteins is currently unknown. To provide insights into the signaling mechanism, two distinct dimeric complexes of the isolated globin domain of the GCS from Bordetella pertussis ( BpeGlobin) were solved via X-ray crystallography in which differences in ligand-bound states were observed. Both monomers of one dimer contain Fe(II)-O states, while the other dimer consists of the Fe(III)-HO and Fe(II)-O states. These data provide the first molecular insights into the heme pocket conformation of the active Fe(II)-O form of these enzymes. In addition, heme distortion modes and heme-protein interactions were found to correlate with the ligation state of the globin, suggesting that these conformational changes play a role in O-dependent signaling. Fourier transform infrared spectroscopy (FTIR) of the full-length GCS from B. pertussis ( BpeGReg) and the closely related GCS from Pectobacterium carotovorum ssp. carotovorum ( PccGCS) confirmed the importance of an ordered water within the heme pocket and two distal residues (Tyr43 and Ser68) as hydrogen-bond donors. Taken together, this work provides mechanistic insights into BpeGReg O sensing and the signaling mechanisms of diguanylate cyclase-containing GCS proteins.

PubMed: 30378421
DOI: 10.1021/acs.inorgchem.8b02584

Experimental method

X-RAY DIFFRACTION (2.3 Å)