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Reduced chlorophyll biosynthesis in heterozygous barley magnesium chelatase mutants

Braumann, Ilka; Stein, Nils and Hansson, Mats LU (2014) In Plant Physiology and Biochemistry 78. p.10-14
Abstract
Chlorophyll biosynthesis is initiated by magnesium chelatase, an enzyme composed of three proteins, which catalyzes the insertion of Mg2+ into protoporphyrin IX to produce Mg-protoporphyrin IX. In barley (Hordeum vulgare L.) the three proteins are encoded by Xantha-f, Xantha-g and Xantha-h. Two of the gene products, XanH and XanG, belong to the structurally conserved family of AAA+ proteins (ATPases associated with various cellular activities) and form a complex involving six subunits of each protein. The complex functions as an ATP-fueled motor of the magnesium chelatase that uses XanF as substrate, which is the catalytic subunit responsible for the insertion of Mg2+ into protoporphyrin IX. Previous studies have shown that semi-dominant... (More)
Chlorophyll biosynthesis is initiated by magnesium chelatase, an enzyme composed of three proteins, which catalyzes the insertion of Mg2+ into protoporphyrin IX to produce Mg-protoporphyrin IX. In barley (Hordeum vulgare L.) the three proteins are encoded by Xantha-f, Xantha-g and Xantha-h. Two of the gene products, XanH and XanG, belong to the structurally conserved family of AAA+ proteins (ATPases associated with various cellular activities) and form a complex involving six subunits of each protein. The complex functions as an ATP-fueled motor of the magnesium chelatase that uses XanF as substrate, which is the catalytic subunit responsible for the insertion of Mg2+ into protoporphyrin IX. Previous studies have shown that semi-dominant Xantha-h mutations result in non-functional XanH subunits that participate in the formation of inactive AAA complexes. In the present study, we identify severe mutations in the barley mutants xantha-h.38, -h.56 and -h.57. A truncated form of the protein is seen in xantha-h.38, whereas no XanH is detected in xantha-h.56 and -h.57. Heterozygous mutants show a reduction in chlorophyll content by 14-18% suggesting a slight semi-dominance of xantha-h.38, -h.56 and -h.57, which otherwise have been regarded as recessive mutations (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Physiology and Biochemistry
volume
78
pages
10 - 14
publisher
Elsevier
external identifiers
  • scopus:84897670628
ISSN
1873-2690
DOI
10.1016/j.plaphy.2014.02.004
language
English
LU publication?
yes
id
93325d4b-a40f-4e25-a76a-38bae068e71a (old id 7758727)
date added to LUP
2015-09-03 12:58:25
date last changed
2017-03-26 03:46:29
@article{93325d4b-a40f-4e25-a76a-38bae068e71a,
  abstract     = {Chlorophyll biosynthesis is initiated by magnesium chelatase, an enzyme composed of three proteins, which catalyzes the insertion of Mg2+ into protoporphyrin IX to produce Mg-protoporphyrin IX. In barley (Hordeum vulgare L.) the three proteins are encoded by Xantha-f, Xantha-g and Xantha-h. Two of the gene products, XanH and XanG, belong to the structurally conserved family of AAA+ proteins (ATPases associated with various cellular activities) and form a complex involving six subunits of each protein. The complex functions as an ATP-fueled motor of the magnesium chelatase that uses XanF as substrate, which is the catalytic subunit responsible for the insertion of Mg2+ into protoporphyrin IX. Previous studies have shown that semi-dominant Xantha-h mutations result in non-functional XanH subunits that participate in the formation of inactive AAA complexes. In the present study, we identify severe mutations in the barley mutants xantha-h.38, -h.56 and -h.57. A truncated form of the protein is seen in xantha-h.38, whereas no XanH is detected in xantha-h.56 and -h.57. Heterozygous mutants show a reduction in chlorophyll content by 14-18% suggesting a slight semi-dominance of xantha-h.38, -h.56 and -h.57, which otherwise have been regarded as recessive mutations},
  author       = {Braumann, Ilka and Stein, Nils and Hansson, Mats},
  issn         = {1873-2690},
  language     = {eng},
  pages        = {10--14},
  publisher    = {Elsevier},
  series       = {Plant Physiology and Biochemistry},
  title        = {Reduced chlorophyll biosynthesis in heterozygous barley magnesium chelatase mutants},
  url          = {http://dx.doi.org/10.1016/j.plaphy.2014.02.004},
  volume       = {78},
  year         = {2014},
}