Molybdoenzyme biosynthesis in Escherichia coli: in vitro activation of purified nitrate reductase from a chlB mutant
| Autor: | D H Boxer, C Romane, Chantal Iobbi-Nivol, Gérard Giordano, Claire-Lise Santini |
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| Rok vydání: | 1992 |
| Předmět: |
Mutant
Coenzymes medicine.disease_cause Nitrate reductase Nitrate Reductase Microbiology Cofactor chemistry.chemical_compound Bacterial Proteins Biosynthesis Nitrate Reductases Metalloproteins Escherichia coli medicine Molecular Biology chemistry.chemical_classification biology Pteridines Molybdopterin Drug Resistance Microbial Molecular biology Enzyme Activation Molecular Weight Kinetics Spectrometry Fluorescence Enzyme chemistry Biochemistry Mutation Chlorates biology.protein Guanosine Triphosphate Molybdenum cofactor Molybdenum Cofactors Research Article |
| Zdroj: | Journal of Bacteriology. 174:7934-7940 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.174.24.7934-7940.1992 |
| Popis: | All molybdoenzyme activities are absent in chlB mutants because of their inability to synthesize molybdopterin guanine dinucleotide, which together with molybdate constitutes the molybdenum cofactor in Escherichia coli. The chlB mutants are able to synthesize molybdopterin. We have previously shown that the inactive nitrate reductase present in a chlB mutant can be activated in a process requiring protein FA and a heat-stable low-molecular-weight substance. We show here that purified nitrate reductase from the soluble fraction of a chlB mutant can be partially activated in a process that requires protein FA, GTP, and an additional protein termed factor X. It appears that the molybdopterin present in the nitrate reductase of a chlB mutant is converted to molybdopterin guanine dinucleotide during activation. The activation is absolutely dependent upon both protein FA and factor X. Factor X activity is present in chlA, chlB, chlE, and chlG mutants. |
| Databáze: | OpenAIRE |
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