Low spin heme A in the heme A biosynthetic protein CtaA from Bacillus subtilis
(1996) In European Journal of Biochemistry p.287-295- Abstract
- Synthesis of heme A from heme B (protoheme IX) most likely occurs in two steps with heme O as an intermediate. Bacillus subtilis CtaB, an integral membrane protein, functions in farnesylation of heme B to form heme O. CtaA, also a membrane protein, is required for heme A synthesis from heme O and appears to be a monooxygenase and/or a dehydrogenase. Wild-type ctaA and ctaB expressed together from plasmids in B. subtilis resulted in CtaA containing equimolar amounts of low-spin heme B and heme A; this form of CtaA was named cyt ba -CTA. A mutant ctaB gene was identified and characterised. It encodes a truncated CtaB polypeptide. Wild-type ctaA and the mutant ctaB gene on plasmids resulted in CtaA containing mainly low-spin heme B; this... (More)
- Synthesis of heme A from heme B (protoheme IX) most likely occurs in two steps with heme O as an intermediate. Bacillus subtilis CtaB, an integral membrane protein, functions in farnesylation of heme B to form heme O. CtaA, also a membrane protein, is required for heme A synthesis from heme O and appears to be a monooxygenase and/or a dehydrogenase. Wild-type ctaA and ctaB expressed together from plasmids in B. subtilis resulted in CtaA containing equimolar amounts of low-spin heme B and heme A; this form of CtaA was named cyt ba -CTA. A mutant ctaB gene was identified and characterised. It encodes a truncated CtaB polypeptide. Wild-type ctaA and the mutant ctaB gene on plasmids resulted in CtaA containing mainly low-spin heme B; this variant was named cyt b -CTA. The heme B component in cyt ba -CTA and cyt b -CTA showed identical properties; a mid-point redox potential of +85 mV, an EPR gmax signal at 3.7, and a split α-band light absorption peak. The heme A component in cyt ba -CTA showed a mid-point potential of +242 mV, an EPR gmax signal at 3.5, and the α-band light absorption peak at 585 nm. It is suggested that the CtaA protein contains two heme binding sites, one for heme B and one for substrate heme. The heme B would play a role in electron transfer, i.e. function as a cytochrome, in the monooxygenase and/or dehydrogenase reaction catalysed by CtaA whereas heme O/heme A would be substrate/product.
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- author
- Svensson, Birgitta ; Anderson, Kristoffer K. and Hederstedt, Lars LU
- organization
- publishing date
- 1996
- type
- Contribution to journal
- publication status
- published
- subject
- in
- European Journal of Biochemistry
- pages
- 287 - 295
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:0029930646
- ISSN
- 0014-2956
- DOI
- 10.1111/j.1432-1033.1996.0287q.x
- language
- English
- LU publication?
- yes
- id
- 4e283da8-ec53-42f3-81c2-a77776c7909f
- date added to LUP
- 2017-07-18 10:05:19
- date last changed
- 2022-01-30 21:32:23
@article{4e283da8-ec53-42f3-81c2-a77776c7909f, abstract = {{Synthesis of heme A from heme B (protoheme IX) most likely occurs in two steps with heme O as an intermediate. Bacillus subtilis CtaB, an integral membrane protein, functions in farnesylation of heme B to form heme O. CtaA, also a membrane protein, is required for heme A synthesis from heme O and appears to be a monooxygenase and/or a dehydrogenase. Wild-type ctaA and ctaB expressed together from plasmids in B. subtilis resulted in CtaA containing equimolar amounts of low-spin heme B and heme A; this form of CtaA was named cyt ba -CTA. A mutant ctaB gene was identified and characterised. It encodes a truncated CtaB polypeptide. Wild-type ctaA and the mutant ctaB gene on plasmids resulted in CtaA containing mainly low-spin heme B; this variant was named cyt b -CTA. The heme B component in cyt ba -CTA and cyt b -CTA showed identical properties; a mid-point redox potential of +85 mV, an EPR gmax signal at 3.7, and a split α-band light absorption peak. The heme A component in cyt ba -CTA showed a mid-point potential of +242 mV, an EPR gmax signal at 3.5, and the α-band light absorption peak at 585 nm. It is suggested that the CtaA protein contains two heme binding sites, one for heme B and one for substrate heme. The heme B would play a role in electron transfer, i.e. function as a cytochrome, in the monooxygenase and/or dehydrogenase reaction catalysed by CtaA whereas heme O/heme A would be substrate/product.<br/>}}, author = {{Svensson, Birgitta and Anderson, Kristoffer K. and Hederstedt, Lars}}, issn = {{0014-2956}}, language = {{eng}}, pages = {{287--295}}, publisher = {{Wiley-Blackwell}}, series = {{European Journal of Biochemistry}}, title = {{Low spin heme A in the heme A biosynthetic protein CtaA from <em>Bacillus subtilis</em>}}, url = {{http://dx.doi.org/10.1111/j.1432-1033.1996.0287q.x}}, doi = {{10.1111/j.1432-1033.1996.0287q.x}}, year = {{1996}}, }