Structure of the Escherichia coli O157:H7 Heme Oxygenase ChuS in Complex with Heme and Enzymatic Inactivation by Mutation of the Heme Coordinating Residue His-193

Suits, M.D.L.; Jaffer, N.; Jia, Zongchao

doi:10.1074/jbc.m607684200

Cited by 43 publications

(50 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1D). All of these residues are conserved in ChuS, and ChuS can also bind heme in this pocket (Suits et al 2006). This is consistent with their possible roles in heme utilization (Suits et al 2005;Schneider et al 2006).…”

Section: Resultssupporting

confidence: 76%

See 1 more Smart Citation

Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens

et al. 2007

View full text Add to dashboard Cite

We report here the crystal structure at 2.0 Å resolution of the AGR_C_4470p protein from the Gramnegative bacterium Agrobacterium tumefaciens. The protein is a tightly associated dimer, each subunit of which bears strong structural homology with the two domains of the heme utilization protein ChuS from Escherichia coli and HemS from Yersinia enterocolitica. Remarkably, the organization of the AGR_C_4470p dimer is the same as that of the two domains in ChuS and HemS, providing structural evidence that these two proteins evolved by gene duplication. However, the binding site for heme, while conserved in HemS and ChuS, is not conserved in AGR_C_4470p, suggesting that it probably has a different function. This is supported by the presence of two homologs of AGR_C_4470p in E. coli, in addition to the ChuS protein.

show abstract

Section: Resultssupporting

confidence: 76%

“…Recently, two crystal structures of heme utilization proteins were reported: heme oxygenase ChuS from Escherichia coli (Suits et al 2005(Suits et al , 2006 and heme transport protein HemS from Yersinia enterocolitica (apo-and heme-bound forms) (Schneider et al 2006). Both proteins are about twice the size of AGR_C_4470p (molecular weight of about 39 kDa).…”

mentioning

confidence: 99%

Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens

et al. 2007

View full text Add to dashboard Cite

show abstract

“…A recent crystal structure of ChuS, a different type of heme oxygenase from E. coli O159:H7, also has a network of water molecules on the distal side of the heme (45). Conversely, in the IsdG-hemin and IsdI-CoPPIX structures, no such water network is present on the distal side to serve as a proton donor to the dioxygen.…”

Section: Discussionmentioning

confidence: 99%

Ruffling of Metalloporphyrins Bound to IsdG and IsdI, Two Heme-degrading Enzymes in Staphylococcus aureus

Lee

Reniere

Skaar

et al. 2008

Journal of Biological Chemistry

101

147

View full text Add to dashboard Cite

IsdG and IsdI are paralogous proteins that are intracellular components of a complex heme uptake system in Staphylococcus aureus. IsdG and IsdI were shown previously to reductively degrade hemin. Crystal structures of the apoproteins show that these proteins belong to a newly identified heme degradation family distinct from canonical eukaryotic and prokaryotic heme oxygenases. Here we report the crystal structures of an inactive N7A variant of IsdG in complex with Fe 3؉ -protoporphyrin IX (IsdG-hemin) and of IsdI in complex with cobalt protoporphyrin IX (IsdI-CoPPIX) to 1.8 Å or better resolution. These structures show that the metalloporphyrins are buried into similar deep clefts such that the propionic acids form salt bridges to two Arg residues. His 77 (IsdG) or His 76 (IsdI), a critical residue required for activity, is coordinated to the Fe 3؉ or Co 3؉ atoms, respectively. The bound porphyrin rings form extensive steric interactions in the binding cleft such that the rings are highly distorted from the plane. This distortion is best described as ruffled and places the ␤-and ␦-meso carbons proximal to the distal oxygen-binding site. In the IsdG-hemin structure, Fe 3؉ is pentacoordinate, and the distal side is occluded by the side chain of Ile 55 . However, in the structure of IsdI-CoPPIX, the distal side of the CoPPIX accommodates a chloride ion in a cavity formed through a conformational change in Ile 55 . The chloride ion participates in a hydrogen bond to the side chain amide of Asn 6 . Together the structures suggest a reaction mechanism in which a reactive peroxide intermediate proceeds with nucleophilic oxidation at the ␤-or ␦-meso carbon of the hemin.Staphylococcus aureus is a leading cause of hospital-acquired bacterial infections (1). The establishment of methicillin-resistant strains of S. aureus is a concern in both the clinic and, more recently, within the community (2, 3). Iron uptake pathways have received significant attention because of the requirement of iron for the growth of most organisms (4). For human pathogens, iron concentrations are limited by host storage, transport, and innate immune mechanisms (2, 5). Many bacterial pathogens have sophisticated systems to directly utilize host iron sources to satisfy their physiological requirements. Heme-iron represents the most abundant iron source in the human body, accounting for ϳ75% of the total iron (6). This heme-iron is predominantly found within hemoglobin in circulating red blood cells and myoglobin of muscle cells. Because of its abundance, an ability to acquire heme-iron from host sources represents a significant advantage for bacterial pathogens (7-9).S. aureus acquires heme-iron predominantly through the Isd (iron-regulated surface determinant) system. IsdA, IsdB, IsdC, and IsdH/HarA are cell wall-anchored proteins (10) that contain heme-binding NEAT domains (11, 12). The host hemoprotein hemoglobin and its carrier protein haptoglobin are bound by IsdB and IsdH at the cell surface. Heme is proposed to be removed from hemoglobin and ...

show abstract

“…The green color of the band is likely due to the presence of degraded heme from activity of E. coli heme oxygenases. 11 The effect of pH was investigated with 50 mM NaP i (binding buffer) at pH values of 6.5-7.5, identified to be optimal for binding. Binding buffer containing 200-500 mM imidazole, at pH 5 or 8 was found to elute Az-Hm14 from the HIS resin (Fig.…”

Section: Affinity Purification Of Az-hm14 and Mbp-hm16mentioning

confidence: 99%

A heme fusion tag for protein affinity purification and quantification

Asher

Bren

2010

Protein Science

View full text Add to dashboard Cite

We report a novel affinity-based purification method for proteins expressed in Escherichia coli that uses the coordination of a heme tag to an L-histidine-immobilized sepharose (HIS) resin. This approach provides an affinity purification tag visible to the eye, facilitating tracking of the protein. We show that azurin and maltose binding protein are readily purified from cell lysate using the heme tag and HIS resin. Mild conditions are used; heme-tagged proteins are bound to the HIS resin in phosphate buffer, pH 7.0, and eluted by adding 200-500 mM imidazole or binding buffer at pH 5 or 8. The HIS resin exhibits a low level of nonspecific binding of untagged cellular proteins for the systems studied here. An additional advantage of the heme tag-HIS method for purification is that the heme tag can be used for protein quantification by using the pyridine hemochrome absorbance method for heme concentration determination.

show abstract

Structure of the Escherichia coli O157:H7 Heme Oxygenase ChuS in Complex with Heme and Enzymatic Inactivation by Mutation of the Heme Coordinating Residue His-193

Cited by 43 publications

References 37 publications

Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens

Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens

Ruffling of Metalloporphyrins Bound to IsdG and IsdI, Two Heme-degrading Enzymes in Staphylococcus aureus

A heme fusion tag for protein affinity purification and quantification

Contact Info

Product

Resources

About