Cloning and characterization of hoxH genes from Arthrospira and Spirulina and application in phylogenetic study.
ABSTRACT Partial hoxH genes of 2 cyanobacterial genera, including 5 strains of Arthrospira and 2 strains of Spirulina, were cloned and characterized. This gene encodes the large subunit of nickel-iron hydrogenase. The results showed that these genes comprised 1349 nucleotides in Arthrospira and 1343 nucleotides in Spirulina, respectively. The GC contents of hoxH were 45.7% to 47.3% in Arthrospira and up to 50.4% to 50.9% in Spirulina. The hoxH gene was demonstrated to be single copy by Southern analysis, and its transcription was verified by reverse transcriptase polymerase chain reaction in Arthrospira platensis FACHB341. The similarities of nucleotide sequences among the 5 strains of Arthrospira ranged from 95.7% to 99.8%, which are higher than those between Arthrospira and Spirulina (72.9-77.0%). However, similarity between the 2 Spirulina strains was only 72.5%, slightly lower than that between the 2 genera. A phylogenetic tree based on hoxH was constructed. All 5 strains of Arthrospira formed a monophyletic clade, which was highly supported by bootstrap value, while the 2 strains of Spirulina were separated into 2 different clades.
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ABSTRACT: We present the results of a phylogenetic study, based on amplified ribosomal DNA restriction analysis of the rDNA operon, of 37 Arthrospira (‘Spirulina’) cultivated clonal strains from four continents. In addition, duplicates from different culture collections or markedly different morphotypes of particular strains established as clonal cultures were treated as separate entries, resulting in a total of 51 tested cultures. The strain Spirulina laxissima SAG 256.80 was included as outgroup. The 16S rRNA genes appeared too conserved for discrimination of the strains by amplified ribosomal DNA restriction analysis, and thus the internally transcribed spacer was selected as molecular taxonomic marker. The internally transcribed spacer sequences situated between the 16S and the 23S rRNA were amplified by polymerase chain reaction and yielded amplicons of about 540 bp. Direct use of cells for polymerase chain reaction seemed to inhibit the amplification reaction. This was overcome by the design of a crude lysis protocol and addition of bovine serum albumin in the polymerase chain reaction mix.The amplicons were digested with four restriction enzymes (EcoRV, HhaI, HinfI, MseI) and the banding patterns obtained were analyzed. Cluster analysis showed the separation of all the strains into two main clusters. No clear relationships could be observed between this division into two clusters and the geographic origin of the strains, or their designation in the culture collections, or their morphology.FEMS Microbiology Letters 02/1999; 172(2):213 - 222. · 2.05 Impact Factor
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ABSTRACT: The sequence pattern CxxCxnGxCxxxGxmGCPP, thus far found in the small subunits from 21 different nickel hydrogenases, appears also to be present in the PSST polypeptide from NADH:ubiquinone oxidoreductase (Complex I) of beef-heart mitochondria. There is only one difference: the first cysteine residue is a leucine in the PSST subunit. The large nickel-binding subunit of nickel hydrogenases shows a surprising homology with the 49 kDa subunit of mitochondrial Complex I.Biochimica et Biophysica Acta 10/1993; 1144(2):221-4. · 4.66 Impact Factor
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ABSTRACT: The bidirectional hydrogenase in cyanobacteria is a tetrameric, NAD+-de pendent enzyme, loosely associated with the cytoplasmic membrane. Two of the subunits, HoxH and HoxY, are homologous to dimeric [Ni-Fe]-hydrogenases whereas the remaining two subunits, HoxF and HoxU, constitute the diaphorase moiety of the enzyme. There is an evolutionary relationship between the latter two subunits and components of complex I of the respiratory chain, localized in the mitochondrial membrane of eukaryotes (NADH:ubiquinone oxidoreductase) and in the cytoplasmic membrane of prokaryotes (NADH-dehydrogenase I). In cyanobacteria, an oxidation of NADH, catalyzed by NADH-dehydroNaturwissenschaften 12/1996; 83(11):525-7. · 2.14 Impact Factor