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Duplication of hyp genes involved in maturation of [NiFe] hydrogenases in Alcaligenes eutrophus H16
- Source :
- Archives of microbiology. 170(6)
- Publication Year :
- 1998
-
Abstract
- Alcaligenes eutrophus H16 harbors seven hyp genes (hypA, B, F, C, D, E, and X) as part of the hydrogenase gene cluster on megaplasmid pHG1. Here we demonstrate that three of the hyp genes (hypA, B, and F) are duplicated in A. eutrophus, which explains the lack of a phenotypic change in single-site mutants impaired in one of the two copies. Mutants with lesions in both copies showed clear alterations in hydrogenase activities. Deletions in hypF1 and hypF2 completely abolished activities of the soluble hydrogenase and of the membrane-bound hydrogenase, mutations in hypA1 and hypA2 totally blocked the membrane-bound hydrogenase activity, while residual soluble hydrogenase activity accounted for the extremely slow growth of the strain on H2. Both hydrogenase activities of mutants defective in hypB1 and hypB2 were partially restored by elevating the concentration of nickel chloride in the medium. Reduction of hydrogenase activities in the double mutants correlated with varying degrees of maturation deficiency based upon the amount of unprocessed nickel-free hydrogenase precursor. Despite a high identity between the two copies of hyp gene products, substantial structural differences were identified between the two copies of hypF genes. HypF1, although functionally active, is a truncated version of HypF2, whose structure resembles HypF proteins of other organisms. Interestingly, the N-terminus of HypF2, which is missing in the HypF1 counterpart, contains a putative acylphosphatase domain in addition to a potential metal binding site.
- Subjects :
- Hydrogenase
Time Factors
Genotype
Mutant
Blotting, Western
Molecular Sequence Data
Biology
Acylphosphatase
Biochemistry
Microbiology
Bacterial Proteins
Genes, Duplicate
Gene duplication
Gene cluster
Genetics
Cloning, Molecular
Molecular Biology
Gene
chemistry.chemical_classification
Base Sequence
Membrane Proteins
General Medicine
Phenotype
Enzyme
chemistry
Genes, Bacterial
Mutation
Cupriavidus necator
Sequence Alignment
Subjects
Details
- ISSN :
- 03028933
- Volume :
- 170
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- Archives of microbiology
- Accession number :
- edsair.doi.dedup.....c5b51452d4c6e5a795cac7f71466e61f