Insertional Mutations in the Hydrogenase vhc and frc Operons Encoding Selenium-Free Hydrogenases in Methanococcus voltae
نویسندگان
چکیده
منابع مشابه
Fusion of two subunits does not impair the function of a [NiFeSe]-hydrogenase in the archaeon Methanococcus voltae.
[NiFe]-hydrogenases generally carry the bimetallic Ni-Fe reaction center on their largest subunit. The [NiFeSe]-hydrogenase Vhu from Methanococcus voltae has an unusual subunit composition. Some of the amino acids participating in the formation of the reaction center are within a separate, very small subunit, called VhuU. It consists of only 25 amino acids and contains the selenocysteinyl resid...
متن کاملTranscriptional regulation of genes encoding the selenium-free [NiFe]-hydrogenases in the archaeon Methanococcus voltae involves positive and negative control elements.
Methanococcus voltae harbors genetic information for two pairs of homologous [NiFe]-hydrogenases. Two of the enzymes contain selenocysteine, while the other two gene groups encode apparent isoenzymes that carry cysteinyl residues in the homologous positions. The genes coding for the selenium-free enzymes, frc and vhc, are expressed only under selenium limitation. They are transcribed out of a c...
متن کاملChemotaxis in the archaebacterium Methanococcus voltae.
The archaebacterium Methanococcus voltae, was shown to be chemotactic. Acetate, isoleucine, and leucine were identified as attractants; whereas histidine was not an attractant. A motile, generally nonchemotactic mutant was isolated.
متن کاملDimethylselenide demethylation is an adaptive response to selenium deprivation in the archaeon Methanococcus voltae.
The archaeon Methanococcus voltae needs selenium for optimal growth. A gene group most likely involved in the demethylation of dimethylselenide was discovered, the expression of which is induced upon selenium deprivation. The operon comprises open reading frames for a corrinoid protein and two putative methyltransferases. It is shown that the addition of dimethylselenide to selenium-depleted gr...
متن کاملHydrogenases of Methanococcus maripaludis
The methanogens catalyze a major component of the Earth’s H2 cycle. They are especially active in anaerobic environments where they are the primary consumers of fermentatively produced H2. These strictly anaerobic Archaea have evolved unique adaptations to H2 metabolism, many of which are poorly understood. Our research examines the enzymes and pathways in H2 metabolism in methanogens, especial...
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ژورنال
عنوان ژورنال: Applied and Environmental Microbiology
سال: 1995
ISSN: 0099-2240,1098-5336
DOI: 10.1128/aem.61.5.1770-1775.1995