Browsing by Author "Karahanian, E"

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    Cloning and molecular analysis of a cDNA and the Cs-mnp1 gene encoding a manganese peroxidase isoenzyme from the lignin-degrading basidiomycete Ceriporiopsis subvermispora
    (1998) Lobos, S; Larrondo, L; Salas, L; Karahanian, E; Vicuña, R
    A cDNA (MnP13-1) and the Cs-mnp1 gene encoding for an isoenzyme of manganese peroxidase (MnP) from C. subvermispora were isolated separately and sequenced. The cDNA, identified in a library constructed in the vector Lambda ZIPLOX, contains 1285 nucleotides, excluding the poly(A) tail, and has a 63% G + C content. The deduced protein sequence shows a high degree of identity with MnPs from other fungi. The mature protein contains 364 amino acids, which are preceded by a 24-amino-acid leader sequence. Consistent with the peroxidase mechanism of MnP, the proximal histidine, the distal histidine and the distal arginine are conserved, although the aromatic binding site (L/V/I-P-X-P) is less hydrophilic than those of other peroxidases. A gene coding for the same protein (Cs-mnp1) was isolated from a genomic library constructed in Lambda GEM-11 vector using the cDNA MnP13-1 as a probe. A subcloned SacI fragment of 2.5 kb contained the complete sequence of the Cs-mnp1 gene, including 162 bp and 770 bp of the upstream and downstream regions, respectively. The Cs-mnp1 gene possesses seven short intervening sequences. The intron splice junction sequences as well as the putative internal lariat formation sites adhere to the GT-AG and CTRAY rules, respectively. To examine the structure of the regulatory region of the Cs-mnp1 gene further, a fragment of 1.9 kb was amplified using inverse PCR. A putative TATAA element was identified 5' of the translational start codon. Also, an inverted CCAAT element, SP-1 and AP-2 sites and several putative heat-shock and metal response elements were identified. (C) 1998 Elsevier Science B.V.
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    lip-like genes in Phanerochaete sordida, and Ceriporiopsis subvermispora, white rot fungi with no detectable lignin peroxidase activity
    (1996) Rajakumar, S; Gaskell, J; Cullen, D; Lobos, S; Karahanian, E; Vicuna, R
    Lignin peroxidase-like genes were PCR amplified from Phanerochaete sordida and Ceriporiopsis subvermispora, fungi lacking lignin peroxidase (LiP) activity. Amplification products were highly similar to previously described LiP genes. Using reverse transcription-coupled PCR a LiP-like cDNA clone was amplified from P. sordida RNA. In contrast, no evidence was obtained for transcription of C. subvermispora LiP genes.
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    New Implications for the Melanocortin System in Alcohol Drinking Behavior in Adolescents: The Glial Dysfunction Hypothesis
    (2017) Orellana Roca, Juan Andrés; Cerpa Nebott, Waldo Francisco; Carvajal, M; Lerma, J; Karahanian, E; Osorio, C; Quintanilla Gómez, Rodrigo Arthur
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    Structure and expression of a laccase gene from the ligninolytic basidiomycete Ceriporiopsis subvermispora
    (1998) Karahanian, E; Corsini, G; Lobos, S; Vicuña, R
    A gene encoding laccase has been isolated from a genomic library of the white-rot basidiomycete Ceriporiopsis subvermispora constructed in Lambda GEM-ii. This gene (Cs-lcs1) contains an open reading frame of 2215 bp, encoding a mature protein of 499 amino acids with a 21-residue signal peptide. The protein sequence exhibits between 63 and 68% identity with laccases from other basidiomycetes and shares with all of them 10 conserved histidines and one cysteine involved in the coordination of copper atoms at the active site of the enzyme. The gene possesses ii introns, with splicing junctions and internal lariat formation sites adhering to the GT-AG and CTRAY rules, respectively. The upstream region of Cs-lcsl contains a TATA box, two CAAT sites, five putative metal response elements and a ACE1 element. In agreement with the presence of the latter element, transcription of Cs-lcsl is activated by copper and silver, as shown by Northern blot and reverse transcription followed by DNA amplification analyses. Based on Southern blot analysis, Cs-lcsl appears to be the only gene encoding laccase in C. subvermispora. (C) 1998 Elsevier Science B.V. All rights reserved.