| 1. |
- Hall, Michael, 1980-, et al.
(författare)
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Purification, crystallization and preliminary X-ray analysis of PPD6, a PsbP-domain protein from Arabidopsis thaliana
- 2012
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Ingår i: Acta Crystallographica. Section F. - 1744-3091 .- 1744-3091. ; 68:3, s. 278-280
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Tidskriftsartikel (refereegranskat)abstract
- The PsbP protein is an extrinsic component of photosystem II that together with PsbO and PsbQ forms the thylakoid lumenal part of the oxygen-evolving complex in higher plants. In addition to PsbP, the thylakoid lumen contains two PsbP-like proteins (PPLs) and six PsbP-domain proteins (PPDs). While the functions of the PsbP-like proteins PPL1 and PPL2 are currently under investigation, the function of the PsbP-domain proteins still remains completely unknown. PPD6 is unique among the PsbP family of proteins in that it contains a conserved disulfide bond which can be reduced in vitro by thioredoxin. The crystal structure determination of the PPD6 protein has been initiated in order to elucidate its function and to gain deeper insights into redox-regulation pathways in the thylakoid lumen. PPD6 has been expressed, purified and crystallized and preliminary X-ray diffraction data have been collected. The crystals belonged to space group P2(1), with unit-cell parameters a = 47.0, b = 64.3, c = 62.0 Å, β = 94.2°, and diffracted to a maximum d-spacing of 2.1 Å.
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| 2. |
- Mishra, Yogesh, et al.
(författare)
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Expression, purification, crystallization and preliminary X-ray crystallographic studies of alkyl hydroperoxide reductase (AhpC) from the cyanobacterium Anabaena sp. PCC 7120
- 2011
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Ingår i: Acta Crystallographica. Section F. - : International Union of Crystallography. - 1744-3091 .- 1744-3091. ; 67:10, s. 1203-1206
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Tidskriftsartikel (refereegranskat)abstract
- Alkyl hydroperoxide reductase (AhpC) is a key component of a large family of thiol-specific antioxidant (TSA) proteins distributed among prokaryotes and eukaryotes. AhpC is involved in the detoxification of reactive oxygen species (ROS) and reactive sulfur species (RSS). Sequence analysis of AhpC from the cyanobacterium Anabaena sp. PCC 7120 shows that this protein belongs to the 1-Cys class of peroxiredoxins (Prxs). It has recently been reported that enhanced expression of this protein in Escherichia coli offers tolerance to multiple stresses such as heat, salt, copper, cadmium, pesticides and UV-B. However, the structural features and the mechanism behind this process remain unclear. To provide insights into its biochemical function, AhpC was expressed, purified and crystallized by the hanging-drop vapour-diffusion method. Diffraction data were collected to a maximum d-spacing of 2.5 Å using synchrotron radiation. The crystal belonged to space group P212121, with unit-cell parameters a = 80, b = 102, c = 109.6 Å. The structure of AhpC from Anabaena sp. PCC 7120 was determined by molecular-replacement methods using the human Prx enzyme hORF6 (PDB entry1prx) as the template.
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| 3. |
- Schubert, Maria, et al.
(författare)
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Plasmodesmata distribution and sugar partitioning in nitrogen-fixing root nodules of Datisca glomerata
- 2011
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Ingår i: Planta. - : Springer Science and Business Media LLC. - 0032-0935 .- 1432-2048. ; 233:1, s. 139-152
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Tidskriftsartikel (refereegranskat)abstract
- To understand carbon partitioning in roots and nodules of Datisca glomerata, activities of sucrose-degrading enzymes and sugar transporter expression patterns were analyzed in both organs, and plasmodesmal connections between nodule cortical cells were examined by transmission electron microscopy. The results indicate that in nodules, the contribution of symplastic transport processes is increased in comparison to roots, specifically in infected cells which develop many secondary plasmodesmata. Invertase activities are dramatically reduced in nodules as compared to roots, indicating that here the main enzyme responsible for the cleavage of sucrose is sucrose synthase. A high-affinity, low-specificity monosaccharide transporter whose expression is induced in infected cells prior to the onset of bacterial nitrogen fixation, and which has an unusually low pH optimum and may be involved in turgor control or hexose retrieval during infection thread growth.
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