RESUMO
A fragment of Penicillium canescens genomic DNA carrying the xlnR gene coding for a translational activator of xylanolytic genes was isolated. It was demonstrated that a loss of this function in genetically modified transformants resulted in a drastic decrease in the production of P. canescens major xylanases and had a negative effect on the syntheses of several other extracellular xylanases. An increase in the dose of the xlnR gene elevated the xylanolytic activity as well as the activities of a number of other auxiliary enzymes involved in xylan degradation. The activities of two P. canescens major secreted enzymes--beta-galactosidase and alpha-L-arabinofuranosidase-appeared weakly dependent on the translational activator xlnR.
Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Penicillium/enzimologia , Transativadores/fisiologia , Xilosidases/biossíntese , Sequência de Aminoácidos , Sequência de Bases , Deleção de Genes , Dosagem de Genes , Genes Fúngicos , Genoma Fúngico , Glicosídeo Hidrolases/biossíntese , Glicosídeo Hidrolases/genética , Dados de Sequência Molecular , Penicillium/genética , Transativadores/genética , Transformação Genética , Xilanos/metabolismo , Xilosidases/genéticaRESUMO
The complete gene xylA that encodes endo-1,4-beta-xylanase secreted by Penicillium canescens was cloned and sequenced. The coding region of the gene is separated by eight introns. The protein comprises 302 amino acids of the mature protein and 25 amino acids of the signal peptide. The xylanase of P. canescens belongs to the glycosyl hydrolase family 10. Nucleotide sequences for binding catabolite repression protein CREA and transactivator protein were detected in the promoter region. A set of multicopy strains displaying a seven-eightfold increase in xylanase yield was obtained. The fraction of xylanase in most productive strains amounted to 30-50% of the total secreted protein.
Assuntos
Genes Fúngicos , Penicillium/enzimologia , Xilosidases/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Fúngico , Eletroforese em Gel de Poliacrilamida , Endo-1,4-beta-Xilanases , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Temperatura , Transativadores/metabolismo , Xilosidases/metabolismoRESUMO
Results of examination of 53 patients in remote periods after operation for closed and open traumas of the liver are presented. Two thirds of the patients were found to be practically healthy and one third had complaints of pains in the abdomen (duodenal ulcer was diagnosed in 1 patient, gastroduodenitis in 3 patients, adhesion disease of the abdominal cavity in 14 patients). Biochemical and radionuclide examinations have established disturbances of some liver functions in a number of patients.
