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In vivo and in vitro studies of Bacillus subtilis ferrochelatase mutants suggest substrate channeling in the heme biosynthesis pathway.

Olsson, Ulf LU ; Billberg, Annika LU ; Sjövall Larsen, Sara LU ; Al-Karadaghi, Salam LU and Hansson, Mats LU (2002) In Journal of Bacteriology 184(14). p.4018-4024
Abstract
Ferrochelatase (EC 4.99.1.1) catalyzes the last reaction in the heme biosynthetic pathway. The enzyme was studied in the bacterium Bacillus subtilis, for which the ferrochelatase three-dimensional structure is known. Two conserved amino acid residues, S54 and Q63, were changed to alanine by site-directed mutagenesis in order to detect any function they might have. The effects of these changes were studied in vivo and in vitro. S54 and Q63 are both located at helix alpha3. The functional group of S54 points out from the enzyme, while Q63 is located in the interior of the structure. None of these residues interact with any other amino acid residues in the ferrochelatase and their function is not understood from the three-dimensional... (More)
Ferrochelatase (EC 4.99.1.1) catalyzes the last reaction in the heme biosynthetic pathway. The enzyme was studied in the bacterium Bacillus subtilis, for which the ferrochelatase three-dimensional structure is known. Two conserved amino acid residues, S54 and Q63, were changed to alanine by site-directed mutagenesis in order to detect any function they might have. The effects of these changes were studied in vivo and in vitro. S54 and Q63 are both located at helix alpha3. The functional group of S54 points out from the enzyme, while Q63 is located in the interior of the structure. None of these residues interact with any other amino acid residues in the ferrochelatase and their function is not understood from the three-dimensional structure. The exchange S54A, but not Q63A, reduced the growth rate of B. subtilis and resulted in the accumulation of coproporphyrin III in the growth medium. This was in contrast to the in vitro activity measurements with the purified enzymes. The ferrochelatase with the exchange S54A was as active as wild-type ferrochelatase, whereas the exchange Q63A caused a 16-fold reduction in V(max). The function of Q63 remains unclear, but it is suggested that S54 is involved in substrate reception or delivery of the enzymatic product. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Support, Non-U.S. Gov't, Structure-Activity Relationship, Site-Directed, Mutagenesis, Iron : metabolism, Heme : biosynthesis, Ferrochelatase : physiology, Ferrochelatase : chemistry, Bacillus subtilis : metabolism, Ferritin : metabolism, Zinc : metabolism
in
Journal of Bacteriology
volume
184
issue
14
pages
4018 - 4024
publisher
American Society for Microbiology
external identifiers
  • pmid:12081974
  • wos:000176582200030
  • scopus:0036302651
ISSN
0021-9193
DOI
10.1128/JB.184.14.4018-4024.2002
language
English
LU publication?
yes
id
eaf164ee-7931-4ee7-902e-d31582301f15 (old id 108994)
date added to LUP
2007-07-09 08:54:37
date last changed
2017-02-19 03:31:46
@article{eaf164ee-7931-4ee7-902e-d31582301f15,
  abstract     = {Ferrochelatase (EC 4.99.1.1) catalyzes the last reaction in the heme biosynthetic pathway. The enzyme was studied in the bacterium Bacillus subtilis, for which the ferrochelatase three-dimensional structure is known. Two conserved amino acid residues, S54 and Q63, were changed to alanine by site-directed mutagenesis in order to detect any function they might have. The effects of these changes were studied in vivo and in vitro. S54 and Q63 are both located at helix alpha3. The functional group of S54 points out from the enzyme, while Q63 is located in the interior of the structure. None of these residues interact with any other amino acid residues in the ferrochelatase and their function is not understood from the three-dimensional structure. The exchange S54A, but not Q63A, reduced the growth rate of B. subtilis and resulted in the accumulation of coproporphyrin III in the growth medium. This was in contrast to the in vitro activity measurements with the purified enzymes. The ferrochelatase with the exchange S54A was as active as wild-type ferrochelatase, whereas the exchange Q63A caused a 16-fold reduction in V(max). The function of Q63 remains unclear, but it is suggested that S54 is involved in substrate reception or delivery of the enzymatic product.},
  author       = {Olsson, Ulf and Billberg, Annika and Sjövall Larsen, Sara and Al-Karadaghi, Salam and Hansson, Mats},
  issn         = {0021-9193},
  keyword      = {Support,Non-U.S. Gov't,Structure-Activity Relationship,Site-Directed,Mutagenesis,Iron : metabolism,Heme : biosynthesis,Ferrochelatase : physiology,Ferrochelatase : chemistry,Bacillus subtilis : metabolism,Ferritin : metabolism,Zinc : metabolism},
  language     = {eng},
  number       = {14},
  pages        = {4018--4024},
  publisher    = {American Society for Microbiology},
  series       = {Journal of Bacteriology},
  title        = {In vivo and in vitro studies of Bacillus subtilis ferrochelatase mutants suggest substrate channeling in the heme biosynthesis pathway.},
  url          = {http://dx.doi.org/10.1128/JB.184.14.4018-4024.2002},
  volume       = {184},
  year         = {2002},
}