Cloning and Structure of the Human Adrenodoxin Gene

Chang, Chih-Hao; Wu, Du An; Lai, Char Chang; Miller, Walter L.; Chung, Bon Chu

doi:10.1089/dna.1988.7.609

Cited by 54 publications

(16 citation statements)

References 29 publications

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“…5). However, two aspartate residues, corresponding to Asp69 and Asp72 in the FdVI sequence, were shown by site- (Chang et al, 1988), putidaredoxin (Tanaka et al, 1974), Cuulohucter crescentus Fd (accession number X51607 in Swiss Prot data base) and E. coli Fd (Fa and Vickery, 1992) are shown. Conserved residues are boxed.…”

Section: Primary Structure Of R Capsulatus Fdvimentioning

confidence: 99%

Purification of a sixth ferredoxin from Rhodobacter capsulatus

Naud¹,

Vincon

Garin

et al. 1994

European Journal of Biochemistry

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A new ferredoxin has been purified from the photosynthetic bacterium Rhodobacter capsulatus. It is the sixth ferredoxin to be isolated from this bacterium and it was called FdVI.Its primary structure was established based on amino acid sequence analysis of the protein and of peptides derived from it. It is composed of 106 residues including five cysteines. The calculated mass of the polypeptide is 11402.6 Da which matches the experimental value determined by electrospray mass spectrometry. Amino acid sequence comparison revealed that ferredoxin VI (FdVI) is strikingly similar to a ferredoxin from Caulobacter crescentus and to the putidaredoxin from Pseudomonas putida.FdVI exhibited an ultraviolet-visible absorption spectrum typical for a [2Fe-2S] ferredoxin. EPR spectroscopy of the reduced protein showed a nearly axial signal similar to that of mitochondria1 and €? putida ferredoxins.FdVI is biosynthesized in cells growing anaerobically under either nitrogen-sufficient or nitrogen-deficient conditions. Although the function of FdVI is unknown, its structural resemblance to [2Fe-2S] ferredoxins known to transfer electrons to oxygenases such as P-450 cytochromes, suggests that FdVI may have a similar role in R. capsulatus.The photosynthetic bacterium Rhodobacter capsulatus is a facultative phototroph endowed with remarkable abilities of metabolic adaptation. It can grow autotrophically or heterotrophically either in the light or in darkness and can choose between five different growth modes (Madigan and Gest, 1979). It is also capable of fixing molecular nitrogen through a metabolic process which has been extensively studied by biochemical (Hallenbeck et al., 1982a; and genetic approaches (Willison et al., 1985;Klipp et al., 1988). Nitrogen fixation is catalyzed by nitrogenase and requires ATP and a low-potential reductant. Two types of electron-carrier proteins, ferredoxins (Fd) and flavodoxins, are known to serve as electron donors to nitrogenase. In R. capsulatus, the identification of the actual physiological reductant of nitrogenase is complicated by the occurence in this bacterium of an exceptional diversity of electron carriers. Five distinct ferredoxins have been isolated and biochemically characterized; three of them, FdI, FdII and FdIII, appear as representative molecular forms of the dicluster ferredoxins found in a wide range of bacteria (Bruschi and Guerlesquin, 1988). FdI and the homodimeric FdIII, both contain two [4Fe-4S] clusters/monomer (Hallenbeck et al.,

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Section: Primary Structure Of R Capsulatus Fdvimentioning

confidence: 99%

Purification of a sixth ferredoxin from Rhodobacter capsulatus

Naud¹,

Vincon

Garin

et al. 1994

European Journal of Biochemistry

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“…This finding is uncommon among genes for steroidogenic enzymes, but is typical of "housekeeping" genes expressed in most tissues (32). While it is attractive to regard adrenodoxin reductase as simply a housekeeping gene because of its broad tissue distribution of expression and its function as a "generic" electron-transport protein for all mitochondrial forms of P450, it should also be noted that adrenodoxin, which has a similar role, is encoded by a gene having a classical TATA box (11). Thus elucidation of the significance of this promoter structure in the adrenodoxin reductase gene will require further experimentation.…”

Section: Methodsmentioning

confidence: 99%

“…Adrenodoxin cDNA is found in three different forms, differing only in their sites of polyadenylylation (10). Nevertheless there are two genes for adrenodoxin (11,12) on chromosome 11q13-+qter (13), while two adrenodoxin pseudogenes are found on chromosomes 20cen-*ql3.1 (13) and on chromosome 21 (12). Adrenodoxin reductase cDNA sequencing suggests that the mRNA undergoes alternate splicing into two different forms, with the less abundant form containing 18 nucleotides encoding six amino acids in the middle of the protein (14).…”

mentioning

confidence: 99%

Cloning and sequence of the human adrenodoxin reductase gene.

Lin

Shi

Miller

1990

Proc. Natl. Acad. Sci. U.S.A.

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Adrenodoxin reductase (ferrodoxin:NADP+ oxidoreductase, EC 1.18.1.2) is a flavoprotein mediating electron transport to all mitochondrial forms of cytochrome P450. We cloned the human adrenodoxin reductase gene and characterized it by restriction endonuclease mapping and DNA sequencing. The entire gene is approximately 12 kilobases long and consists of 12 exons. The first exon encodes the first 26 of the 32 amino acids of the signal peptide, and the second exon encodes the remainder of signal peptide and the apparent FAD binding site. The remaining 10 exons are clustered in a region of only 4.3 kilobases, separated from the first two exons by a large intron of about 5.6 kilobases. Two forms of human adrenodoxin reductase mRNA, differing by the presence or absence of 18 bases in the middle of the sequence, arise from alternate splicing at the 5' end of exon 7. This alternately spliced region is directly adjacent to the NADPH binding site, which is entirely contained in exon 6. The immediate 5' flanking region lacks TATA and CAAT boxes; however, this region is rich in G+C and contains six copies of the sequence GGGCGGG, resembling promoter sequences of "housekeeping" genes. RNase protection experiments show that transcription is initiated from multiple sites in the 5' flanking region, located about 21-91 base pairs upstream from the AUG translational initiation codon.The conversion of cholesterol to pregnenolone is the first and rate-limiting step in the synthesis of all steroid hormones. This reaction is mediated by the mitochondrial cholesterol side chain-cleavage enzyme, cytochrome P450scc (reviewed in ref.

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“…There is only one human gene for adrenodoxin reductase, located on chromosome 17q24-q25 (17)(18)(19) that is expressed in all human tissues examined, (20) hence a disorder in this gene should have effects extending far beyond the steroidogenic tissues. Similarly, there are one (21) or two (22) nearly identical genes for adrenodoxin closely linked on chromosome 1 1q22 (19,22,23) that encode identical proteins (23); this mRNA is also found in all tissues examined (24). Thus, it has generally been agreed that congenital lipoid adrenal hyperplasia represents a genetic defect in the human P450scc gene (1,25).…”

Section: Introductionmentioning

confidence: 99%

Normal genes for the cholesterol side chain cleavage enzyme, P450scc, in congenital lipoid adrenal hyperplasia.

Lin¹,

Gitelman²,

Saenger³

et al. 1991

J. Clin. Invest.

116

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Congenital lipoid adrenal hyperplasia is the most severe form of congenital adrenal hyperplasia. Affected individuals can synthesize no steroid hormones, and hence are all phenotypic females with a severe salt-losing syndrome that is fatal if not treated in early infancy. All previous studies have suggested that the disorder is in the cholesterol side chain cleavage enzyme (P450scc), which converts cholesterol to pregnenolone. A newborn patient was diagnosed by the lack of significant concentrations of adrenal or gonadal steroids either before or after stimulation with corticotropin (ACTH) or gonadotropin (hCG). The P450scc gene in this patient and in a previously described patient were grossly intact, as evidenced by Southern blotting patterns. Enzymatic (polymerase chain reaction) amplification and sequencing of the coding regions of their P450scc genes showed these were identical to the previously cloned human P450scc cDNA and gene sequences. Undetected compound heterozygosity was ruled out in the new patient by sequencing P450scc cDNA enzymatically amplified from gonadal RNA. Northern blots of gonadal RNA from this patient contained normal sized mRNAs for P450scc and also for adrenodoxin reductase, adrenodoxin, sterol carrier protein 2, endozepine, and GRP-78 (the precursor to steroidogenesis activator peptide). These studies show that lipoid CAH is not caused by lesions in the P450scc gene, and suggest that another unidentified factor is required for the conversion of cholesterol to pregnenolone, and is disordered in congenital lipoid adrenal hyperplasia. (J. Clin. Invest. 1991.88:1955-1962

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Cloning and Structure of the Human Adrenodoxin Gene

Cited by 54 publications

References 29 publications

Purification of a sixth ferredoxin from Rhodobacter capsulatus

Purification of a sixth ferredoxin from Rhodobacter capsulatus

Cloning and sequence of the human adrenodoxin reductase gene.

Normal genes for the cholesterol side chain cleavage enzyme, P450scc, in congenital lipoid adrenal hyperplasia.

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