A noncanonical heme oxygenase specific for the degradation of c-type heme

Li, Shuxin; Isiorho, Eta A; Owens, Victoria; Donnan, Patrick H.; Odili, Chidinma L.; Mansoorabadi, Steven O.

doi:10.1016/j.jbc.2021.100666

Cited by 9 publications

(10 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There was, however, some evidence of heme loss by the protein, as quantification on the basis of total protein yielded a specific activity of 12.4 ± 0.8 μM DCPIP μM cyt P460 –1 min –1 . While we do not observe formation of a peptide-linked biliverdin, we cannot rule it out on the basis of UV/vis and would need HPLC and MS analysis of the products, which is beyond the scope of this work . Nevertheless, the restoration of WT cyt P460 spectroscopic properties as well as NH 2 OH oxidation activity to inactive proenzyme produced during anaerobic expression strongly evidences the peroxide dependence of cyt P460 cofactor maturation.…”

Section: Resultsmentioning

confidence: 68%

“…While we do not observe formation of a peptide-linked biliverdin, we cannot rule it out on the basis of UV/vis and would need HPLC and MS analysis of the products, which is beyond the scope of this work. 31 Nevertheless, the restoration of WT cyt P460 spectroscopic properties as well as NH 2 OH oxidation activity to inactive proenzyme produced during anaerobic expression strongly S7), suggesting that compound I is not formed by the proenzyme.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Cytochrome P460 Cofactor Maturation Proceeds via Peroxide-Dependent Post-translational Modification

et al. 2023

View full text Add to dashboard Cite

Cytochrome P460s are heme enzymes that oxidize hydroxylamine to nitrous oxide. They bear specialized “heme P460” cofactors that are cross-linked to their host polypeptides by a post-translationally modified lysine residue. Wild-type N. europaea cytochrome P460 may be isolated as a cross-link-deficient proenzyme following anaerobic overexpression in E. coli. When treated with peroxide, this proenzyme undergoes maturation to active enzyme with spectroscopic and catalytic properties that match wild-type cyt P460. This maturation reactivity requires no chaperonesit is intrinsic to the protein. This behavior extends to the broader cytochrome c′β superfamily. Accumulated data reveal key contributions from the secondary coordination sphere that enable selective, complete maturation. Spectroscopic data support the intermediacy of a ferryl species along the maturation pathway.

show abstract

Section: Resultsmentioning

confidence: 68%

Section: ■ Results and Discussionmentioning

confidence: 99%

Cytochrome P460 Cofactor Maturation Proceeds via Peroxide-Dependent Post-translational Modification

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The one exception is Pden_1323, from Paracoccus denitrificans , who also belongs to the HugZ family. Pden_1323 lacks the C-terminal loop that contains the axial heme ligand (His245 in HugZ) but degrades heme c bound to a cytochrome fragment (MP11) ( Li et al., 2021 ). In cytochrome c, the heme iron is coordinated by a histidine in proteaceous region attached to heme c and that histidine is retained in MP11 ( Kranz et al., 2009 ).…”

Section: Resultsmentioning

confidence: 99%

“…Some pathogenic bacteria utilize proteins from the flavin mononucleotide (FMN)-binding subfamily for heme-binding or degradation, such as HugZ from Helicobacter pylori (which produces δ-biliverdin) and ChuZ from Campylobacter jejuni ( Hu et al., 2011 ; Zhang et al., 2011 ). Pden_1323, from Paracoccus denitrificans , is a member of this family, and while it lacks the conserved axial heme ligand from HugZ and ChuZ, it can degrade fragments of heme c ( Li et al., 2021 ).…”

Section: Introductionmentioning

confidence: 99%

HupZ, a Unique Heme-Binding Protein, Enhances Group A Streptococcus Fitness During Mucosal Colonization

Lyles

Thomas²,

Ouellette³

et al. 2022

Front. Cell. Infect. Microbiol.

View full text Add to dashboard Cite

Group A Streptococcus (GAS) is a major pathogen that causes simple and invasive infections. GAS requires iron for metabolic processes and pathogenesis, and heme is its preferred iron source. We previously described the iron-regulated hupZ in GAS, showing that a recombinant HupZ-His6 protein binds and degrades heme. The His6 tag was later implicated in heme iron coordination by HupZ-His6. Hence, we tested several recombinant HupZ proteins, including a tag-free protein, for heme binding and degradation in vitro. We established that HupZ binds heme but without coordinating the heme iron. Heme-HupZ readily accepted exogenous imidazole as its axial heme ligand, prompting degradation. Furthermore, HupZ bound a fragment of heme c (whose iron is coordinated by the cytochrome histidine residue) and exhibited limited degradation. GAS, however, did not grow on a heme c fragment as an iron source. Heterologous HupZ expression in Lactococcus lactis increased heme b iron use. A GAS hupZ mutant showed reduced growth when using hemoglobin as an iron source, increased sensitivity to heme toxicity, and decreased fitness in a murine model for vaginal colonization. Together, the data demonstrate that HupZ contributes to heme metabolism and host survival, likely as a heme chaperone. HupZ is structurally similar to the recently described heme c-degrading enzyme, Pden_1323, suggesting that the GAS HupZ might be divergent to play a new role in heme metabolism.

show abstract

“…In contrast to HO-1, the IsdG family of HOs converts heme to a mixture of formaldehyde and staphylobilin rather than biliverdins ( Matsui et al, 2013 ). PigA and the HO groups containing the HemS motif convert heme into β and δ isoforms of BV ( Friedman et al, 2004 ; Onzuka et al, 2017 ; Li et al, 2021 ). Additionally, the HO group belonging to the FMN binding-like superfamily, such as HugZ, HutZ, and HupZ, also converts heme to either β or δ isoforms of BV ( Lyles and Eichenbaum, 2018 ).…”

Section: Discussionmentioning

confidence: 99%

Heme oxygenase-independent bilin biosynthesis revealed by a hmox1 suppressor screening in Chlamydomonas reinhardtii

et al. 2022

View full text Add to dashboard Cite

Bilins are open-chain tetrapyrroles synthesized in phototrophs by successive enzymic reactions catalyzed by heme oxygenases (HMOXs/HOs) and ferredoxin-dependent biliverdin reductases (FDBRs) that typically serve as chromophore cofactors for phytochromes and phycobiliproteins. Chlamydomonas reinhardtii lacks both phycobiliproteins and phytochromes. Nonetheless, the activity and stability of photosystem I (PSI) and the catalytic subunit of magnesium chelatase (MgCh) named CHLH1 are significantly reduced and phototropic growth is significantly attenuated in a hmox1 mutant that is deficient in bilin biosynthesis. Consistent with these findings, previous studies on hmox1 uncovered an essential role for bilins in chloroplast retrograde signaling, maintenance of a functional photosynthetic apparatus, and the direct regulation of chlorophyll biosynthesis. In this study, we generated and screened a collection of insertional mutants in a hmox1 genetic background for suppressor mutants with phototropic growth restored to rates observed in wild-type 4A+ C. reinhardtii cells. Here, we characterized a suppressor of hmox1 named ho1su1 with phototrophic growth rates and levels of CHLH1 and PSI proteins similar to 4A+. Tetrad analysis indicated that a plasmid insertion co-segregated with the suppressor phenotype of ho1su1. Results from TAIL-PCR and plasmid rescue experiments demonstrated that the plasmid insertion was located in exon 1 of the HMOX1 locus. Heterologous expression of the bilin-binding reporter Nostoc punctiforme NpF2164g5 in the chloroplast of ho1su1 indicated that bilin accumulated in the chloroplast of ho1su1 despite the absence of the HMOX1 protein. Collectively, our study reveals the presence of an alternative bilin biosynthetic pathway independent of HMOX1 in the chloroplasts of Chlamydomonas cells.

show abstract

A noncanonical heme oxygenase specific for the degradation of c-type heme

Cited by 9 publications

References 51 publications

Cytochrome P460 Cofactor Maturation Proceeds via Peroxide-Dependent Post-translational Modification

Cytochrome P460 Cofactor Maturation Proceeds via Peroxide-Dependent Post-translational Modification

HupZ, a Unique Heme-Binding Protein, Enhances Group A Streptococcus Fitness During Mucosal Colonization

Heme oxygenase-independent bilin biosynthesis revealed by a hmox1 suppressor screening in Chlamydomonas reinhardtii

Contact Info

Product

Resources

About