A physical map of Nicotiana tabacum plastid DNA including the location of structural genes for ribosomal RNAs and the large subunit of ribulose bisphosphate carboxylase/oxygenase

1981 ◽  
Vol 3 (3) ◽  
pp. 189-204 ◽  
Author(s):  
Patrick Seyer ◽  
Klaus V. Kowallik ◽  
Reinhold G. Herrmann
Keyword(s):  
Nicotiana Tabacum ◽  
Physical Map ◽  
Large Subunit ◽  
Plastid Dna ◽  
Ribulose Bisphosphate Carboxylase ◽  
Structural Genes ◽  
Ribulose Bisphosphate ◽  
Ribosomal Rnas ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Daffodil Chromoplast DNA: Comparison with Chloroplast DNA, Physical Map, and Gene Localization

1987 ◽  
Vol 42 (1-2) ◽  
pp. 118-122 ◽  
Author(s):  
Paul Hansmann
Keyword(s):  
Chloroplast Dna ◽  
Physical Map ◽  
Large Subunit ◽  
Plastid Dna ◽  
Cytochrome F ◽  
Restriction Endonucleases ◽  
Gene Localization ◽  
Ribulose Bisphosphate Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Abstract In daffodil, development of chloroplasts or chromoplasts is not accompanied by plastid DNA modification. This has been shown by comparing the fragment pattern of different restriction endonucleases, and by the lack of methylation of CCGG sequences. A physical map has been constructed for the plastome using the restriction endonucleases Sal I, Pst I, and Bgl I. The fragments containing the genes for the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL), the alpha, beta, and epsilon subunits of the ATP synthase complex (atpA , atpB, atpE ), cytochrome f(petA ), and for the 51 kDa chlorophyll apoprotein of photosystem II (psbB) have been identified. The respective gene locations correspond to those on spinach chloroplast DNA.

The CO2/O2 specificity of single-subunit ribulose-bisphosphate carboxylase from the dinoflagellate, Amphidinium carterae

1998 ◽  
Vol 25 (2) ◽  
pp. 131 ◽  
Author(s):  
Spencer M. Whitney ◽  
T. John Andrews
Keyword(s):  
Large Subunit ◽  
Anaerobic Bacteria ◽  
Carbon Gain ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Amphidinium Carterae ◽  
Bisphosphate Carboxylase ◽  
Cell Extracts ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Alternate Substrate

Some dinoflagellates have been shown recently to be unique among eukaryotes in having a ribulose-bisphosphate carboxylase-oxygenase (Rubisco, EC 4.1.1.39) composed of only one type of subunit, the 53-kDa large subunit [reviewed by Palmer, J.D. (1996) Plant Cell 8, 343–345]. Formerly, such homomeric Rubiscos had been found only in anaerobic bacteria and are characterised by such poor abilities to discriminate against the competitive alternate substrate, O2, that they would not be able to support net carbon gain if exposed to the current atmospheric CO2/O2 ratio. The capacity of Rubiscos from aerobic organisms to discriminate more effectively against O2 appeared to correlate with the presence of additional 12- to 18-kDa small subunits. Thus the CO2/O2 specificity of the homomeric dinoflagellate Rubisco is of considerable interest from the structural, physiological and evolutionary viewpoints. However, for unknown reasons, Rubiscos from dinoflagellates studied so far are so unstable after extraction from the cells that kinetic characterisation has not been possible. We redesigned two methods for measuring Rubisco’s CO2/O2 specificity to adapt them to rapid measurement at 10°C using unfractionated cell extracts. Both methods revealed that the CO2/O2 specificity of Rubisco from the dinoflagellate, Amphidinium carterae Hulburt, was approximately twice as great as that of other homomeric Rubiscos but unlikely to be sufficient to support dinoflagellate photosynthesis without assistance from an inorganic-carbon-concentrating mechanism.

Changes in the net charge and subunit properties of ribulose bisphosphate carboxylase–oxygenase during cold hardening of Puma rye

1979 ◽  
Vol 57 (2) ◽  
pp. 155-164 ◽  
Author(s):  
N. P. A. Huner ◽  
F. D. H. Macdowall
Keyword(s):  
Molecular Weight ◽  
Large Subunit ◽  
Sodium Dodecyl ◽  
Reducing Agent ◽  
Cold Hardening ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Thaw Cycle ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Ribulose bisphosphate carboxylase–oxygenase (RUBPCase) from leaves of cold-hardened and unhardened Puma rye was purified by gel filtration and ion exchange chromatography. The specific activity of the hardened form was twice that of the unhardened form. A difference in charge between the two forms of this enzyme was proved by gel electrofocussing. The estimated isoelectric point (pI) values were 6.4 and 6.3 for the enzyme from the hardened and unhardened source respectively. The large subunit (55 000 molecular weight) of the enzyme from only the unhardened source formed an apparent dimer during sodium dodecyl sulfate (SDS) gel electrophoresis. At pH 6.8 it was also the source of an anomalous polypeptide with an apparent molecular weight of 47 000. This anomalous polypeptide appeared in both hardened and unhardened preparations after irreversible inactivation of RUBPCase activity by NaCl. It also appeared after preparation of the purified enzymes for SDS–PAGE in the absence of β-mercaptoethanol, but this was reversible. The enzyme from the hardened source was less affected in the absence of reducing agent. Structural evidence was obtained for the previously reported cold hardening of the enzyme against freeze inactivation. A freeze–thaw cycle applied to the enzyme in vitro caused some polymerization of the large subunit and its anomalous polypeptide, in the absence of reducing agent, especially in the unhardened case. This increased with repeated cycles until the fifth cycle when the large subunit monomer and its satellite were abolished only in preparations from the unhardened source. These data indicate that the large subunit is a probable site of change that occurred in this enzyme during cold hardening.

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