Compact archaeal variant of heme A synthase

FEBS Letters ◽  
2006 ◽  
Vol 580 (22) ◽  
pp. 5351-5356 ◽  
Author(s):  
Anna Lewin ◽  
Lars Hederstedt
Keyword(s):  
Heme A Synthase

scholarly journals Heme A Synthase Enzyme Functions Dissected by Mutagenesis of Bacillus subtilis CtaA

2005 ◽  
Vol 187 (24) ◽  
pp. 8361-8369 ◽  
Author(s):  
Lars Hederstedt ◽  
Anna Lewin ◽  
Mimmi Throne-Holst
Keyword(s):  
Bacillus Subtilis ◽  
Catalytic Mechanism ◽  
Enzyme Reaction ◽  
Prosthetic Group ◽  
Histidine Residues ◽  
Functional Roles ◽  
Heme A Synthase ◽  
Respiratory Oxidases

ABSTRACT Heme A, as a prosthetic group, is found exclusively in respiratory oxidases of mitochondria and aerobic bacteria. Bacillus subtilis CtaA and other heme A synthases catalyze the conversion of a methyl side group on heme O into a formyl group. The catalytic mechanism of heme A synthase is not understood, and little is known about the composition and structure of the enzyme. In this work, we have: (i) constructed a ctaA deletion mutant and a system for overproduction of mutant variants of the CtaA protein in B. subtilis, (ii) developed anaffinity purification procedure for isolation of preparative amounts of CtaA, and (iii) investigated the functional roles of four invariant histidine residues in heme A synthase by in vivo and in vitro analyses of the properties of mutant variants of CtaA. Our results show an important function of three histidine residues for heme A synthase activity. Several of the purified mutant enzyme proteins contained tightly bound heme O. One variant also contained trapped hydroxylated heme O, which is a postulated enzyme reaction intermediate. The findings indicate functional roles for the invariant histidine residues and provide strong evidence that the heme A synthase enzyme reaction includes two consecutive monooxygenations.

scholarly journals The Heme a Synthase Cox15 Associates with Cytochrome c Oxidase Assembly Intermediates during Cox1 Maturation

2013 ◽  
Vol 33 (20) ◽  
pp. 4128-4137 ◽  
Author(s):  
B. Bareth ◽  
S. Dennerlein ◽  
D. U. Mick ◽  
M. Nikolov ◽  
H. Urlaub ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Heme A Synthase

Heme O Synthase and Heme A Synthase fromBacillus subtilisandRhodobacter sphaeroidesInteract inEscherichia coli†

Biochemistry ◽  
2004 ◽  
Vol 43 (42) ◽  
pp. 13541-13548 ◽  
Author(s):  
Brienne M. Brown ◽  
Zhihong Wang ◽  
Kenneth R. Brown ◽  
Julia A. Cricco ◽  
Eric L. Hegg
Keyword(s):  
Inescherichia Coli ◽  
Heme A Synthase

scholarly journals Isolated Heme A Synthase from Aquifex aeolicus Is a Trimer

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Hui Zeng ◽  
Guoliang Zhu ◽  
Shuangbo Zhang ◽  
Xinmei Li ◽  
Janosch Martin ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Integral Membrane Protein ◽  
Proper Function ◽  
Cellular Respiration ◽  
Molecular Architecture ◽  
Aquifex Aeolicus ◽  
Oligomeric State ◽  
Wide Range ◽  
Oligomeric Complex ◽  
Heme A Synthase

ABSTRACT The integral membrane protein heme A synthase (HAS) catalyzes the biosynthesis of heme A, which is a prerequisite for cellular respiration in a wide range of aerobic organisms. Previous studies have revealed that HAS can form homo-oligomeric complexes, and this oligomerization appears to be evolutionarily conserved among prokaryotes and eukaryotes and is shown to be essential for the biological function of eukaryotic HAS. Despite its importance, little is known about the detailed structural properties of HAS oligomers. Here, we aimed to address this critical issue by analyzing the oligomeric state of HAS from Aquifex aeolicus (AaHAS) using a combination of techniques, including size exclusion chromatography coupled with multiangle light scattering (SEC-MALS), cross-linking, laser-induced liquid bead ion desorption mass spectrometry (LILBID-MS), and single-particle electron cryomicroscopy (cryo-EM). Our results show that HAS forms a thermostable trimeric complex. A cryo-EM density map provides information on the oligomerization interface of the AaHAS trimer. These results provide structural insights into HAS multimerization and expand our knowledge of this important enzyme. IMPORTANCE Heme A is a vital redox cofactor unique for the terminal cytochrome c oxidase in mitochondria and many microorganisms. It plays a key role in oxygen reduction by serving as an electron carrier and as the oxygen-binding site. Heme A is synthesized from heme O by an integral membrane protein, heme A synthase (HAS). Defects in HAS impair cellular respiration and have been linked to various human diseases, e.g., fatal infantile hypertrophic cardiomyopathy and Leigh syndrome. HAS exists as a stable oligomeric complex, and studies have shown that oligomerization of eukaryotic HAS is necessary for its proper function. However, the molecular architecture of the HAS oligomeric complex has remained uncharacterized. The present study shows that HAS forms trimers and reveals how the oligomeric arrangement contributes to the complex stability and flexibility, enabling HAS to perform its catalytic function effectively. This work provides the basic understanding for future studies on heme A biosynthesis.

scholarly journals Crystal structure of heme A synthase from Bacillus subtilis

2018 ◽  
Vol 115 (47) ◽  
pp. 11953-11957 ◽  
Author(s):  
Satomi Niwa ◽  
Kazuki Takeda ◽  
Masayuki Kosugi ◽  
Erika Tsutsumi ◽  
Tatsushi Mogi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bacillus Subtilis ◽  
Transmembrane Helix ◽  
Integral Membrane Protein ◽  
Heme Binding ◽  
Terminal Oxidases ◽  
Domain Structures ◽  
Heme A Synthase ◽  
Insight Into ◽  
Heme Molecule

Heme A is an essential cofactor for respiratory terminal oxidases and vital for respiration in aerobic organisms. The final step of heme A biosynthesis is formylation of the C-8 methyl group of heme molecule by heme A synthase (HAS). HAS is a heme-containing integral membrane protein, and its structure and reaction mechanisms have remained unknown. Thus, little is known about HAS despite of its importance. Here we report the crystal structure of HAS from Bacillus subtilis at 2.2-Å resolution. The N- and C-terminal halves of HAS consist of four-helix bundles and they align in a pseudo twofold symmetry manner. Each bundle contains a pair of histidine residues and forms a heme-binding domain. The C-half domain binds a cofactor-heme molecule, while the N-half domain is vacant. Many water molecules are found in the transmembrane region and around the substrate-binding site, and some of them interact with the main chain of transmembrane helix. Comparison of these two domain structures enables us to construct a substrate-heme binding state structure. This structure implies that a completely conserved glutamate, Glu57 in B. subtilis, is the catalytic residue for the formylation reaction. These results provide valuable suggestions of the substrate-heme binding mechanism. Our results present significant insight into the heme A biosynthesis.

Heme A Synthase Does Not Incorporate Molecular Oxygen into the Formyl Group of Heme A†

Biochemistry ◽  
2004 ◽  
Vol 43 (27) ◽  
pp. 8616-8624 ◽  
Author(s):  
Kenneth R. Brown ◽  
Brienne M. Brown ◽  
Emily Hoagland ◽  
Charles L. Mayne ◽  
Eric L. Hegg
Keyword(s):  
Molecular Oxygen ◽  
Formyl Group ◽  
Heme A Synthase

scholarly journals The Assembly Factor Pet117 Couples Heme a Synthase Activity to Cytochrome Oxidase Assembly

2016 ◽  
Vol 292 (5) ◽  
pp. 1815-1825 ◽  
Author(s):  
Nicholas G. Taylor ◽  
Samantha Swenson ◽  
Nicholas J. Harris ◽  
Edward M. Germany ◽  
Jennifer L. Fox ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Assembly Factor ◽  
Heme A Synthase

Identification of Novel Hemes Generated by Heme A Synthase:  Evidence for Two Successive Monooxygenase Reactions†

Biochemistry ◽  
2002 ◽  
Vol 41 (36) ◽  
pp. 10906-10913 ◽  
Author(s):  
Kenneth R. Brown ◽  
Brienne M. Allan ◽  
Peter Do ◽  
Eric L. Hegg
Keyword(s):  
Heme A Synthase
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