Abstract
Site-directed mutations were created in the cyanobacterium Synechocystis 6803 to alter specific histidine residues of the photosystem II (PS II) D2 protein. In one mutant (tyr-197), the his-197 residue was replaced by tyrosine, in another mutant (asn-214), his-214 was changed into asparagine. The tyr-197 mutant did not show any low-temperature fluorescence attributable to PS II, but contained a PSII chlorophyll-protein, CP-47, in significant quantities. Another PS II chlorophyll-protein, CP-43, was absent, as was PS II-related herbicide binding. The asn-214 mutant showed a blue-shifted low-temperature fluorescence maximum around 682 nm, but did not have a significant amount of membrane-incorporated CP-43 or CP-47. Herbicide binding was also absent in this mutant. These data indicate a very important role of the his-197 and his-214 residues in the D2 protein, and are interpreted to support the hypothesis that the D2 protein and the M subunit from the photosynthetic reaction center of purple bacteria have analogous functions. According to this hypothesis, his-197 is involved in binding of P680. and his-214 forms ligands with QA and Fe2+. In absence of a functional D2 protein, the PS II core complex appears to be destabilized as evidenced by loss of chlorophyll-proteins inthe mutants.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 762-768 |
| Number of pages | 7 |
| Journal | Zeitschrift fur Naturforschung - Section C Journal of Biosciences |
| Volume | 42 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 1987 |
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Keywords
- Cyanobacteria
- Herbicide Binding
- Photosynthesis
- Photosystem II Proteins
- Site-Directed Mutagenesis
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
Cite this
Site-directed mutations of two histidine residues in the D2 protein inactivate and destabilize photosystem ii in the cyanobacterium synechocystis 6803. / Vermaas, Willem; Williams, John G K; Arntzen, Charles J.
In: Zeitschrift fur Naturforschung - Section C Journal of Biosciences, Vol. 42, No. 6, 01.06.1987, p. 762-768.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Site-directed mutations of two histidine residues in the D2 protein inactivate and destabilize photosystem ii in the cyanobacterium synechocystis 6803
AU - Vermaas, Willem
AU - Williams, John G K
AU - Arntzen, Charles J.
PY - 1987/6/1
Y1 - 1987/6/1
N2 - Site-directed mutations were created in the cyanobacterium Synechocystis 6803 to alter specific histidine residues of the photosystem II (PS II) D2 protein. In one mutant (tyr-197), the his-197 residue was replaced by tyrosine, in another mutant (asn-214), his-214 was changed into asparagine. The tyr-197 mutant did not show any low-temperature fluorescence attributable to PS II, but contained a PSII chlorophyll-protein, CP-47, in significant quantities. Another PS II chlorophyll-protein, CP-43, was absent, as was PS II-related herbicide binding. The asn-214 mutant showed a blue-shifted low-temperature fluorescence maximum around 682 nm, but did not have a significant amount of membrane-incorporated CP-43 or CP-47. Herbicide binding was also absent in this mutant. These data indicate a very important role of the his-197 and his-214 residues in the D2 protein, and are interpreted to support the hypothesis that the D2 protein and the M subunit from the photosynthetic reaction center of purple bacteria have analogous functions. According to this hypothesis, his-197 is involved in binding of P680. and his-214 forms ligands with QA and Fe2+. In absence of a functional D2 protein, the PS II core complex appears to be destabilized as evidenced by loss of chlorophyll-proteins inthe mutants.
AB - Site-directed mutations were created in the cyanobacterium Synechocystis 6803 to alter specific histidine residues of the photosystem II (PS II) D2 protein. In one mutant (tyr-197), the his-197 residue was replaced by tyrosine, in another mutant (asn-214), his-214 was changed into asparagine. The tyr-197 mutant did not show any low-temperature fluorescence attributable to PS II, but contained a PSII chlorophyll-protein, CP-47, in significant quantities. Another PS II chlorophyll-protein, CP-43, was absent, as was PS II-related herbicide binding. The asn-214 mutant showed a blue-shifted low-temperature fluorescence maximum around 682 nm, but did not have a significant amount of membrane-incorporated CP-43 or CP-47. Herbicide binding was also absent in this mutant. These data indicate a very important role of the his-197 and his-214 residues in the D2 protein, and are interpreted to support the hypothesis that the D2 protein and the M subunit from the photosynthetic reaction center of purple bacteria have analogous functions. According to this hypothesis, his-197 is involved in binding of P680. and his-214 forms ligands with QA and Fe2+. In absence of a functional D2 protein, the PS II core complex appears to be destabilized as evidenced by loss of chlorophyll-proteins inthe mutants.
KW - Cyanobacteria
KW - Herbicide Binding
KW - Photosynthesis
KW - Photosystem II Proteins
KW - Site-Directed Mutagenesis
UR - http://www.scopus.com/inward/record.url?scp=84961487659&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84961487659&partnerID=8YFLogxK
U2 - 10.1515/znc-1987-0620
DO - 10.1515/znc-1987-0620
M3 - Article
VL - 42
SP - 762
EP - 768
JO - Zeitschrift fur Naturforschung - Section C Journal of Biosciences
JF - Zeitschrift fur Naturforschung - Section C Journal of Biosciences
SN - 0939-5075
IS - 6
ER -