8SMU

Integral fusion of the HtaA CR2 domain from Corynebacterium diphtheriae within EGFP

Summary for 8SMU

• Entry DOI: 10.2210/pdb8smu/pdb
• Descriptor: HtaACR2 integral fusion within enhanced green fluorescent protein, PROTOPORPHYRIN IX CONTAINING FE, GLYCEROL, ... (6 entities in total)
• Functional Keywords: heme-binding domain, green fluorescent protein, integral fusion, fluorescent protein
• Biological source: Aequorea victoria; More
• Total number of polymer chains: 4
• Total formula weight: 181671.14

Authors

Mahoney, B.J.,Cascio, D.,Clubb, R.T. (deposition date: 2023-04-26, release date: 2023-09-27, Last modification date: 2024-11-13)

Primary citation

Mahoney, B.J.,Goring, A.K.,Wang, Y.,Dasika, P.,Zhou, A.,Grossbard, E.,Cascio, D.,Loo, J.A.,Clubb, R.T.
Development and atomic structure of a new fluorescence-based sensor to probe heme transfer in bacterial pathogens.
J.Inorg.Biochem., 249:112368-112368, 2023

PubMed Abstract: Heme is the most abundant source of iron in the human body and is actively scavenged by bacterial pathogens during infections. Corynebacterium diphtheriae and other species of actinobacteria scavenge heme using cell wall associated and secreted proteins that contain Conserved Region (CR) domains. Here we report the development of a fluorescent sensor to measure heme transfer from the C-terminal CR domain within the HtaA protein (CR2) to other hemoproteins within the heme-uptake system. The sensor contains the CR2 domain inserted into the β2 to β3 turn of the Enhanced Green Fluorescent Protein (EGFP). A 2.45 Å crystal structure reveals the basis of heme binding to the CR2 domain via iron-tyrosyl coordination and shares conserved structural features with CR domains present in Corynebacterium glutamicum. The structure and small angle X-ray scattering experiments are consistent with the sensor adopting a V-shaped structure that exhibits only small fluctuations in inter-domain positioning. We demonstrate heme transfer from the sensor to the CR domains located within the HtaA or HtaB proteins in the heme-uptake system as measured by a ∼ 60% increase in sensor fluorescence and native mass spectrometry.

PubMed: 37729854
DOI: 10.1016/j.jinorgbio.2023.112368

Experimental method

X-RAY DIFFRACTION (2.45 Å)