Heme A synthase enzyme functions dissected by mutagenesis of Bacillus subtilis CtaA
(2005) In Journal of Bacteriology 187(24). p.8361-8369- 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 0 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 an affinity 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... (More)
- 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 0 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 an affinity 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 0, 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. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/210918
- author
- Hederstedt, Lars LU ; Lewin, Anna LU and Throne-Holst, Mimmi
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Bacteriology
- volume
- 187
- issue
- 24
- pages
- 8361 - 8369
- publisher
- American Society for Microbiology
- external identifiers
-
- wos:000233880000018
- pmid:16321940
- scopus:28844505581
- ISSN
- 0021-9193
- DOI
- 10.1128/JB.187.24.8361-8369.2005
- language
- English
- LU publication?
- yes
- id
- 9670ba82-cbbd-4c26-a3fb-9c6f3f533071 (old id 210918)
- date added to LUP
- 2016-04-01 11:57:57
- date last changed
- 2022-01-26 20:49:32
@article{9670ba82-cbbd-4c26-a3fb-9c6f3f533071,
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 0 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 an affinity 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 0, 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.}},
author = {{Hederstedt, Lars and Lewin, Anna and Throne-Holst, Mimmi}},
issn = {{0021-9193}},
language = {{eng}},
number = {{24}},
pages = {{8361--8369}},
publisher = {{American Society for Microbiology}},
series = {{Journal of Bacteriology}},
title = {{Heme A synthase enzyme functions dissected by mutagenesis of <em>Bacillus subtilis</em> CtaA}},
url = {{http://dx.doi.org/10.1128/JB.187.24.8361-8369.2005}},
doi = {{10.1128/JB.187.24.8361-8369.2005}},
volume = {{187}},
year = {{2005}},
}