Thermodynamics of Heme Binding to the HasASMHemophore:  Effect of Mutations at Three Key Residues for Heme Uptake†

Biochemistry ◽  
2003 ◽  
Vol 42 (36) ◽  
pp. 10627-10633 ◽  
Author(s):  
Clarisse Deniau ◽  
Robert Gilli ◽  
Nadia Izadi-Pruneyre ◽  
Sylvie Létoffé ◽  
Muriel Delepierre ◽  
...  
Keyword(s):  
Heme Binding ◽  
Heme Uptake ◽  
Key Residues

Characterization of the Periplasmic Heme-Binding Protein ShuT from the Heme Uptake System ofShigella dysenteriae†

Biochemistry ◽  
2005 ◽  
Vol 44 (39) ◽  
pp. 13179-13191 ◽  
Author(s):  
Suntara Eakanunkul ◽  
Gudrun S. Lukat-Rodgers ◽  
Suganya Sumithran ◽  
Arundhati Ghosh ◽  
Kenton R. Rodgers ◽  
...  
Keyword(s):  
Binding Protein ◽  
Uptake System ◽  
Heme Binding ◽  
Heme Uptake ◽  
Heme Binding Protein

Structural basis for the heme transfer reaction in heme uptake machinery from Corynebacteria

2019 ◽  
Vol 55 (92) ◽  
pp. 13864-13867
Author(s):  
Norifumi Muraki ◽  
Chihiro Kitatsuji ◽  
Yasunori Okamoto ◽  
Takeshi Uchida ◽  
Koichiro Ishimori ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Structural Basis ◽  
Heme Binding ◽  
Heme Uptake ◽  
Heme Transfer

The CR domains in HtaA and HtaB are responsible for heme binding/transport in the heme-uptake machinery in Corynebacteria.

scholarly journals Bacillus anthracis IsdG, a Heme-Degrading Monooxygenase

2006 ◽  
Vol 188 (3) ◽  
pp. 1071-1080 ◽  
Author(s):  
Eric P. Skaar ◽  
Andrew H. Gaspar ◽  
Olaf Schneewind
Keyword(s):  
Staphylococcus Aureus ◽  
Cytochrome P450 ◽  
Bacterial Infection ◽  
Bacillus Anthracis ◽  
Causative Agent ◽  
Protein Product ◽  
Heme Binding ◽  
Cytochrome P450 Reductase ◽  
Heme Uptake ◽  
Heme Oxygenases

ABSTRACT Bacillus anthracis, the causative agent of anthrax, utilizes hemin and hemoglobin for growth in culture, suggesting that these host molecules serve as sources for the nutrient iron during bacterial infection. Bioinformatic analyses of the B. anthracis genome revealed genes with similarity to the iron-regulated surface determinant (isd) system responsible for heme uptake in Staphylococcus aureus. We show that the protein product of one of these genes, isdG, binds hemin in a manner resembling the heme binding of known heme oxygenases. Formation of IsdG:hemin complexes in the presence of a suitable electron donor, e.g., ascorbate or cytochrome P450 reductase, promotes catalytic degradation of hemin to biliverdin with concomitant release of iron. IsdG is required for B. anthracis utilization of hemin as a sole iron source, and it is also necessary for bacterial protection against heme-mediated toxicity. These data suggest that IsdG functions as a heme-degrading monooxygenase in B. anthracis.

scholarly journals The Cytoplasmic Heme-binding Protein (PhuS) from the Heme Uptake System ofPseudomonas aeruginosaIs an Intracellular Heme-trafficking Protein to the δ-Regioselective Heme Oxygenase

2006 ◽  
Vol 281 (19) ◽  
pp. 13652-13662 ◽  
Author(s):  
Ila B. Lansky ◽  
Gudrun S. Lukat-Rodgers ◽  
Darci Block ◽  
Kenton R. Rodgers ◽  
Melanie Ratliff ◽  
...  
Keyword(s):  
Heme Oxygenase ◽  
Binding Protein ◽  
Uptake System ◽  
Heme Binding ◽  
Heme Uptake ◽  
Heme Trafficking ◽  
Heme Binding Protein

Heme dependent transcriptional regulation of the Pseudomonas aeruginosa tandem sRNA prrF1,F2 locus by the cytoplasmic heme binding protein PhuS

2020 ◽  
Author(s):  
Tyree Wilson ◽  
Susana Mouriño ◽  
Angela Wilks
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fluorescence Anisotropy ◽  
Binding Protein ◽  
Transcriptional Regulator ◽  
Opportunistic Pathogen ◽  
Dual Function ◽  
Heme Binding ◽  
Heme Uptake ◽  
Qpcr Analysis ◽  
Heme Binding Protein

Pseudomonas aeruginosa is an opportunistic pathogen requiring iron for its survival and virulence. P. aeruginosa can acquire iron from heme via the heme assimilation system (Has) and Pseudomonas heme uptake (Phu) systems. The Has and Phu systems have non-redundant roles in heme sensing and transport, respectively. However, despite their respective roles heme taken up by either the Has or Phu system is regulated at the metabolic level by the cytoplasmic heme binding protein PhuS, which controls heme flux through the iron-regulated heme oxygenase HemO. Herein, through a combination of CHIP-PCR, EMSA and fluorescence anisotropy we show PhuS binds upstream of the tandem iron-responsive sRNAs prrF1,F2. Furthermore, qPCR analysis of the PAO1 WT and ΔphuS allelic strain shows loss of PhuS abrogates the heme dependent regulation of PrrH. Taken together our data shows PhuS, in addition to its role in regulating extracellular heme metabolism also functions as a transcriptional regulator of the heme-dependent sRNA, PrrH. This dual function of PhuS is central to integrating extracellular heme utilization into the PrrF/PrrH sRNA regulatory network critical for P. aeruginosa adaptation and virulence within the host.

scholarly journals Heme and hemoglobin utilization by Mycobacterium tuberculosis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Avishek Mitra ◽  
Ying-Hui Ko ◽  
Gino Cingolani ◽  
Michael Niederweis
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
Cell Surface ◽  
Human Body ◽  
Iron Acquisition ◽  
Outer Membrane Proteins ◽  
Blood Protein ◽  
Heme Binding ◽  
Heme Uptake ◽  
Substrate Binding Protein

Abstract Iron is essential for growth of Mycobacterium tuberculosis (Mtb), but most iron in the human body is stored in heme within hemoglobin. Here, we demonstrate that the substrate-binding protein DppA of the inner membrane Dpp transporter is required for heme and hemoglobin utilization by Mtb. The 1.27 Å crystal structure of DppA shows a tetrapeptide bound in the protein core and a large solvent-exposed crevice for heme binding. Mutation of arginine 179 in this cleft eliminates heme binding to DppA and prevents heme utilization by Mtb. The outer membrane proteins PPE36 and PPE62 are also required for heme and hemoglobin utilization, indicating that these pathways converge at the cell surface of Mtb. Albumin, the most abundant blood protein, binds heme specifically and bypasses the requirements for PPE36, PPE62 and Dpp. Thus, our study reveals albumin-dependent and -independent heme uptake pathways, highlighting the importance of iron acquisition from heme for Mtb.

Flavin radicals, conformational sampling and robust design principles in interprotein electron transfer: the trimethylamine dehydrogenase-electron-transferring flavoprotein complex

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Molecular Assembly ◽  
Conformational Sampling ◽  
Trimethylamine Dehydrogenase ◽  
Key Residues ◽  
Electron Transferring Flavoprotein ◽  
Electron Transfer Complex

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.

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