CfbA promotes insertion of cobalt and nickel into ruffled tetrapyrroles<i>in vitro</i>

Schuelke-Sanchez, Ariel; Stone, Alissa A; Liptak, Matthew D.

doi:10.1039/c9dt03601f

Cited by 7 publications

(6 citation statements)

References 64 publications

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“…Indeed, the CbiX S from A. fulgidus has very recently been studied with several porphyrinoids, such as uroporphyrin I and uroporphyrin III, that are non-natural substrates for CbiX S and CfbA, suggesting the importance of the “ruffled” states of the tetrapyrrole rings for the chelatase reaction. 24 Although it was not concluded that both the natural substrate SHC and non-natural substrates could behave in a similar manner, the plasticity of the tetrapyrrole substrates may be important for CfbA (or CbiX S )-catalyzed reactions. If the ring fluctuation occurs after the intermediate formation, NH moieties will be positioned near the two His at the opposite site to Ni 2+ , which allows for facile deprotonation of the NH moieties.…”

Section: Resultsmentioning

confidence: 99%

“… 18 Namely, in both types of CfbA enzymes, the chelatase reaction rate for Co 2+ was faster than that for Ni 2+ , which may be shared in ancestral class II chelatases CfbA and CbiX S based on their shared structural features. 24 Considering the structures of Ni 2+ , Co 2+ , Ni-SHC, and Co-SHC-bound forms of CfbA, the difference in the metal-coordination structures of Ni 2+ - and Co 2+ -bound forms is recognized as one of the key features related to the different reaction rates. Although it remains unclear whether a mechanism to distinguish Ni 2+ and Co 2+ exists in CfbA, it will be fruitful to consider the different coordination chemistry types of Co 2+ and Ni 2+ as found in formate- and Glu42-bindings to metals.…”

Section: Resultsmentioning

confidence: 99%

“…18 Namely, in both types of CA enzymes, the chelatase reaction rate for Co 2+ was faster than that for Ni 2+ , which may be shared in ancestral class II chelatases CA and CbiX S based on their shared structural features. 24 Considering the structures of Ni 2+ , Co 2+ , Ni-SHC, and Co-SHC-bound forms of CA, the difference in the metal- . This allows the His residues to facially deprotonation of the SHC NH groups.…”

Section: Activity Assays Of Camentioning

confidence: 99%

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The nickel-sirohydrochlorin formation mechanism of the ancestral class II chelatase CfbA in coenzyme F430 biosynthesis

Fujishiro

Ogawa

2021

Chem. Sci.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Activity Assays Of Camentioning

confidence: 99%

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The nickel-sirohydrochlorin formation mechanism of the ancestral class II chelatase CfbA in coenzyme F430 biosynthesis

Fujishiro

Ogawa

2021

Chem. Sci.

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“…The TRASH proteins in these clusters have two adjacent Cys residues in addition to the four canonical metal-binding Cys residues in the TRASH motif (Cys-Xaa2-Cys-Xaa19-22-Cys-Xaa3-Cys) [30] (Figure 3B); these extra Cys could help ligand a sixcoordinate metal such as cobalt, nickel, or iron. Furthermore, non-Cys THI4 and TRASH genes cluster with genes for proteins from families that transport or metabolize cobalt or nickel [36][37][38][39] (Figure 3A).…”

Section: Genomic Context Of Non-cys Thi4 Genesmentioning

confidence: 99%

Structure and function of aerotolerant, multiple-turnover THI4 thiazole synthases

Joshi

García‐García

et al. 2021

Preprint

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Plant and fungal THI4 thiazole synthases produce the thiamin thiazole moiety in aerobic conditions via a single-turnover suicide reaction that uses an active-site Cys residue as sulfur donor. Multipleturnover (i.e. catalytic) THI4s lacking an active-site Cys (non-Cys THI4s) that use sulfide as sulfur donor have been characterized – but only from archaeal methanogens that are anaerobic, O2-sensitive hyperthermophiles from sulfide-rich habitats. These THI4s prefer iron as cofactor. A survey of prokaryote genomes uncovered non-Cys THI4s in aerobic mesophiles from sulfide-poor habitats, suggesting that multiple-turnover THI4 operation is possible in aerobic, mild, low-sulfide conditions. This was confirmed by testing 23 representative non-Cys THI4s for complementation of an Escherichia coli ΔthiG thiazole auxotroph in aerobic conditions. Sixteen were clearly active, and more so when intracellular sulfide level was raised by supplying Cys, demonstrating catalytic function in the presence of O2 at mild temperatures and indicating use of sulfide or a sulfide metabolite as sulfur donor. Comparative genomic evidence linked non-Cys THI4s with proteins from families that bind, transport, or metabolize cobalt or other heavy metals. The crystal structure of the aerotolerant bacterial Thermovibrio ammonificans THI4 was determined to probe the molecular basis of aerotolerance. The structure suggested no large deviations compared to the structures of THI4s from O2-sensitive methanogens, but is consistent with an alternative catalytic metal. Together with complementation data, the use of cobalt rather than iron was supported. We conclude that catalytic THI4s can indeed operate aerobically and that the metal cofactor inserted is a likely natural determinant of aerotolerance.

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“…It is known that CfbA can utilize not only Ni 2+ , but also Co 2+ as a metal substrate [2,26,27]. The activity for Co 2+ of CfbA is much higher than Ni 2+ .…”

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confidence: 99%

Nickel‐chelatase activity of SirB variants mimicking the His arrangement in the naturally occurring nickel‐chelatase CfbA

Oyamada,

Ogawa,

Fujishiro

2024

FEBS Open Bio

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Metal–tetrapyrrole cofactors are involved in multiple cellular functions, and chelatases are key enzymes for the biosynthesis of these cofactors. CfbA is an ancestral, homodimeric‐type class II chelatase which is able to use not only Ni2+ as a physiological metal substrate, but also Co2+ as a nonphysiological substrate with higher activity than for Ni2+. The Ni/Co‐chelatase function found in CfbA is also observed in SirB, a descendant, monomeric‐type class II chelatase. This is despite the distinct active site structure of CfbA and SirB; specifically, CfbA shows a unique four His residue arrangement, unlike other monomeric class II chelatases such as SirB. Herein, we studied the Ni‐chelatase activity of SirB variants R134H, L200H, and R134H/L200H, the latter of which mimics the His alignment of CfbA. Our results showed that the SirB R134H variant exhibited the highest Ni‐chelatase activity among the SirB enzymes, which in turn suggests that the position of His134 could be more important for the Ni‐chelatase activity than that of His200. The SirB R134H/L200H variant showed lower activity than R134H, despite the four His residues found in SirB R134H/L200H. CD spectroscopy showed secondary structure denaturation and a slight difficulty in Ni‐binding of SirB R134H/L200H, which may be related to its lower activity. Finally, a docking simulation suggested that the His134 of the SirB R134H variant could function as a base catalyst for the Ni‐chelatase reaction in a class II chelatase architecture.

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CfbA promotes insertion of cobalt and nickel into ruffled tetrapyrrolesin vitro

Abstract: CfbA inserts a labile metal into a ruffled tetrapyrrole.

Cited by 7 publications

References 64 publications

The nickel-sirohydrochlorin formation mechanism of the ancestral class II chelatase CfbA in coenzyme F430 biosynthesis

The nickel-sirohydrochlorin formation mechanism of the ancestral class II chelatase CfbA in coenzyme F430 biosynthesis

Structure and function of aerotolerant, multiple-turnover THI4 thiazole synthases

Nickel‐chelatase activity of SirB variants mimicking the His arrangement in the naturally occurring nickel‐chelatase CfbA

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