In vitro-mutagenesis of NADPH:protochlorophyllide oxidoreductase B: two distinctive protochlorophyllide binding sites participate in enzyme catalysis and assembly
| Autor: | Christiane Reinbothe, Steffen Reinbothe, Claire Desvignes, Hélène Pesey, Sandra Bartsch, Francoise Quigley, Frank Buhr |
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| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
Oxidoreductases Acting on CH-CH Group Donors Base Sequence Sequence Homology Amino Acid biology Molecular Sequence Data Mutagenesis Pigment binding Active site General Medicine Catalysis Enzyme Biochemistry chemistry Protochlorophyllide Oxidoreductase Genetics biology.protein Amino Acid Sequence Binding site Plastid Molecular Biology DNA Primers |
| Zdroj: | Molecular Genetics and Genomics. 275:540-552 |
| ISSN: | 1617-4623 1617-4615 |
| DOI: | 10.1007/s00438-006-0109-9 |
| Popis: | NADPH:protochlorophyllide oxidoreductase (POR) B is a key enzyme for the light-induced greening of etiolated angiosperm plants. It is nucleus-encoded, imported into the plastids posttranslationally, and assembled into larger light-harvesting POR:protochlorophyllide complexes termed LHPP (Reinbothe et al., Nature 397:80-84, 1999). An in vitro-mutagenesis approach was taken to study the role of the evolutionarily conserved Cys residues in pigment binding. Four Cys residues are present in the PORB of which two, Cys276 and Cys303, established distinct pigment binding sites, as shown by biochemical tests, protein import studies, and in vitro-reconstitution experiments. While Cys276 constituted the Pchlide binding site in the active site of the enzyme, Cys303 established a second, low affinity pigment binding site that was involved in the assembly and stabilization of imported PORB enzyme inside etioplasts. |
| Databáze: | OpenAIRE |
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