Kinetics of heme transfer by the Shr NEAT domains of Group A Streptococcus

Ouattara, Mahamoudou; Pennati, Andrea; Devlin, Darius J; Huang, Ya-Shu; Gadda, Giovanni; Eichenbaum, Zehava

doi:10.1016/j.abb.2013.08.009

Cited by 21 publications

(16 citation statements)

References 51 publications

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“…In contrast, upstream of IsdC, there is variation in the number of NEAT proteins and the domain architectures of these proteins in different bacterial species, reflecting diversification in the mechanisms for heme capture and heme relay to IsdC. NEAT domain proteins that target Hb as an iron source include IsdX1, IsdX2, and Hal from B. anthracis (30 -33), IlsA from B. cereus (34), and Shr from S. pyogenes (35,68). Each of these proteins contains one or more heme-binding NEAT domains and additional domains with poorly characterized function (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…A homologue of IsdB/H occurs in the related species Staphylococcus lugdunensis (28), which also causes infective endocarditis (29). Functionally related proteins that contain NEAT domains and capture heme from Hb are found in many Gram-positive bacteria including Bacillus anthracis (30 -33), Bacillus cereus (34), and Streptococcus pyogenes (35). The C-terminal NEAT domain of IsdB/H (Fig.…”

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confidence: 99%

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Structure of the Hemoglobin-IsdH Complex Reveals the Molecular Basis of Iron Capture by Staphylococcus aureus

Dickson

Kumar

Jacques

et al. 2014

Journal of Biological Chemistry

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Structure of the Hemoglobin-IsdH Complex Reveals the Molecular Basis of Iron Capture by Staphylococcus aureus

Dickson

Kumar

Jacques

et al. 2014

Journal of Biological Chemistry

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“…Previous studies established that GAS uses dedicated surface receptors and membrane transporters to capture heme from host hemoproteins and relay it through the peptidoglycan layers and into the cytoplasm (Bates et al 2003;Montañez et al 2005;Nygaard et al 2006;Ouattara et al 2010Ouattara et al , 2013Sook et al 2008). GAS imports heme to satisfy nutritional requirements for metal iron (Eichenbaum et al 1996;Ouattara et al 2010).…”

Section: Discussionmentioning

confidence: 98%

“…GAS is a hemolytic bacterium that readily uses hemoglobin and other hemoproteins to satisfy its need for iron (Eichenbaum et al 1996). A heme relay apparatus comprising Shr, Shp, and SiaABC (HtsABC) proteins mediates the capture and delivery of heme into GAS cell (Bates et al 2003;Nygaard et al 2006;Ouattara et al 2010Ouattara et al , 2013Sook et al 2008). A second ABC transporter, SiuADBG, also contributes to heme acquisition in GAS through an unknown mechanism (Montañez et al 2005).…”

Section: Introductionmentioning

confidence: 99%

In vitro heme biotransformation by the HupZ enzyme from Group A streptococcus

et al. 2016

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In Group A streptococcus (GAS), the metallorepressor MtsR regulates iron homeostasis. Here we describe a new MtsR-repressed gene, which we named hupZ (heme utilization protein). A recombinant HupZ protein was purified bound to heme from Escherichia coli grown in the presence of 5-aminolevulinic acid and iron. HupZ specifically binds heme with stoichiometry of 1:1. The addition of NADPH to heme-bound HupZ (in the presence of cytochrome P450 reductase, NADPH-regeneration system and catalase) triggered progressive decrease of the HupZ Soret band and the appearance of an absorption peak at 660 nm that was resistance to hydrolytic conditions. No spectral changes were observed when ferredoxin and ferredoxin reductase were used as redox partners. Differential spectroscopy with myoglobin or with the ferrous chelator, ferrozine, confirmed that carbon monoxide and free iron are produced during the reaction. ApoHupZ was crystallized as a homodimer with a split β-barrel conformation in each monomer comprising six β strands and three α helices. This structure resembles the split β-barrel domain shared by the members of a recently described family of heme degrading enzymes. However, HupZ is smaller and lacks key residues found in the proteins of the latter group. Phylogenetic analysis places HupZ on a clade separated from those for previously described heme oxygenases. In summary, we have identified a new GAS enzyme-containing split β-barrel and capable of heme biotransformation in vitro; to the best of our knowledge, this is the first enzyme among Streptococcus species with such activity.

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“…The two genes upstream express Shr [34,36] and Shp [37,38]. Shr receives heme from hemoglobin [39,40] and transfers it to Shp [36]. Shp, which has two axial methionine ligands [37], transfers heme to SiaA [41] with rate constants that are similar in the oxidized and reduced forms [42–44].…”

Section: Introductionmentioning

confidence: 99%

Heme-bound SiaA from Streptococcus pyogenes: Effects of mutations and oxidation state on protein stability

Akbas

Draganova

Block

et al. 2016

Journal of Inorganic Biochemistry

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The protein SiaA (HtsA) is part of a heme uptake pathway in Streptococcus pyogenes. In this report, we present the heme binding of the alanine mutants of the axial histidine (H229A) and methionine (M79A) ligands, as well as a lysine (K61A) and cysteine (C58A) located near the heme propionates (based on homology modeling) and a control mutant (C47A). pH titrations gave pKa values ranging from 9.0 to 9.5, close to the value of 9.7 for WT SiaA. Resonance Raman spectra of the mutants suggested that the ferric heme environment may be distinct from the wild-type; spectra of the ferrous states were similar. The midpoint reduction potential of the K61A mutant was determined by spectroelectrochemical titration to be 61 ± 3 mV vs. SHE, similar to the wild-type protein (68 ± 3 mV). The addition of guanidine hydrochloride showed two processes for protein denaturation, consistent with heme loss from protein forms differing by the orientation of the heme in the binding pocket (the half-life for the slower process was one to three days). The ease of protein unfolding was related to the strength of interaction of the residues with the heme. We hypothesize that kinetically facile but only partial unfolding, followed by a very slow approach to the completely unfolded state, may be a fundamental attribute of heme trafficking proteins. Small motions to release/transfer the heme accompanied by resistance to extensive unfolding may preserve the three dimensional form of the protein for further uptake and release.

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Kinetics of heme transfer by the Shr NEAT domains of Group A Streptococcus

Cited by 21 publications

References 51 publications

Structure of the Hemoglobin-IsdH Complex Reveals the Molecular Basis of Iron Capture by Staphylococcus aureus

Structure of the Hemoglobin-IsdH Complex Reveals the Molecular Basis of Iron Capture by Staphylococcus aureus

In vitro heme biotransformation by the HupZ enzyme from Group A streptococcus

Heme-bound SiaA from Streptococcus pyogenes: Effects of mutations and oxidation state on protein stability

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