Structure-Function Studies of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase: Activation, Thermostability, and CO2/O2 Specificity
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منابع مشابه
Reduced CO2/O2 specificity of ribulose-bisphosphate carboxylase/oxygenase in a temperature-sensitive chloroplast mutant of Chlamydomonas.
The Chlamydomonas reinhardtii chloroplast mutant 68-4PP is phenotypically indistinguishable from wild type at 25 degrees C but fails to grow photosynthetically at 35 degrees C. It had about 30% of the wild-type level of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) holoenzyme and carboxylase activity when grown at 25 degrees C, but less than 15% when grown at 35 degrees C. Pulse...
متن کاملAssessment of structural and functional divergence far from the large subunit active site of ribulose-1,5-bisphosphate carboxylase/oxygenase.
Despite conservation of three-dimensional structure and active-site residues, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) enzymes from divergent species differ with respect to catalytic efficiency and CO2/O2 specificity. A deeper understanding of the structural basis for these differences may provide a rationale for engineering an improved enzyme, thereby leading to a...
متن کاملCharacterization of ribulose 1,5-bisphosphate carboxylase/oxygenase from Euglena gracilis Z.
An improved method was devised to purify ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) with high specific activity (2.1 mumol of CO2 fixed/mg protein/min) from Euglena gracilis Z. The purified enzyme stored at -80 degrees C required treatment with dithiothreitol for full activity. The dithiothreitol-treated RuBisCO was activated by 12 mM NaHCO3 and 20 mM MgCl2, and the activated sta...
متن کاملDirected mutagenesis of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase. Loop 6 substitutions complement for structural stability but decrease catalytic efficiency.
The structure of active-site loop 6 plays a role in determining the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39). Rubisco from the green alga Chlamydomonas reinhardtii differs from higher plant Rubisco within the loop 6 region, and the C. reinhardtii enzyme has a CO2/O2 specificity 25% lower than that of higher plant enzymes. To examin...
متن کاملPreliminary structural studies of ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum.
Ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) from Rhodospirillum rubrum has been crystallized in a form that is suitable for structural studies by x-ray diffraction. The asymmetric unit of the crystal contains one dimeric enzyme molecule of molecular mass 101,000 Da. The enzyme was activated prior to crystallization and is presumed to be in the CO2-activated state in the crysta...
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