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Titolo:
EXPRESSION OF GENES AND PROCESSING OF ENZYMES FOR THE BIOSYNTHESIS OFPENICILLINS AND CEPHALOSPORINS
Autore:
MARTIN JF; GUTIERREZ S; FERNANDEZ FJ; VELASCO J; FIERRO F; MARCOS AT; KOSALKOVA K;
Indirizzi:
UNIV LEON,FAC BIOL,DEPT ECOL GENET & MICROBIOL,AREA MICROBIOL E-24071LEON SPAIN
Titolo Testata:
Antonie van Leeuwenhoek
fascicolo: 3, volume: 65, anno: 1994,
pagine: 227 - 243
SICI:
0003-6072(1994)65:3<227:EOGAPO>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
ISOPENICILLIN-N SYNTHETASE; COENZYME-A-6-AMINOPENICILLANIC ACID ACYLTRANSFERASE; DEACETOXYCEPHALOSPORIN-C SYNTHETASE; MULTIDOMAIN PEPTIDE SYNTHETASE; CYSTEINYL-VALINE SYNTHETASE; BETA-LACTAM BIOSYNTHESIS; ACETYL COENZYME-A; ACREMONIUM-CHRYSOGENUM; ASPERGILLUS-NIDULANS; STREPTOMYCES-CLAVULIGERUS;
Keywords:
PENICILLIN AND CEPHALOSPORIN BIOSYNTHESIS; PCBAB GENES; PCBC GENES; PENDE GENES; CEFEF GENES; CEFG GENES; TRANSCRIPTION ANALYSIS; PROTEIN PROCESSING; REGULATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
86
Recensione:
Indirizzi per estratti:
Citazione:
J.F. Martin et al., "EXPRESSION OF GENES AND PROCESSING OF ENZYMES FOR THE BIOSYNTHESIS OFPENICILLINS AND CEPHALOSPORINS", Antonie van Leeuwenhoek, 65(3), 1994, pp. 227-243

Abstract

The genes pcbAB, pcbC and penDE encoding the enzymes (alpha-aminoadipyl-cysteinyl-valine synthetase, isopenicillin N synthase and isopenicillin N acyltransferase, respectively) involved in the biosynthesis of penicillin have been cloned from Penicillium chrysogenum and Aspergillus nidulans. They are clustered in chromosome I (10.4 Mb) of P. chrysogenum, in chromosome II of Penicillium notatum (9.6 Mb) and in chromosome VI (3.0 Mb) of A. nidulans. Each gene is expressed as a single transcript from separate promoters. Enzyme regulation studies and gene expression analysis have provided useful information to understand the control of genes involved in penicillin biosynthesis. The enzyme isopenicillin N acyltransferase encoded by the penDE gene is synthesized as a 40 kDa protein that is (self)processed into two subunits of 29 and 11 kDa. Both subunits appear to be required for acyl-CoA 6-APA acyltransferase activity. The isopenicillin N acyltransferase was shown to be located in microbodies, whereas the isopenicillin N synthase has been reported to be present in vesicles of the Golgi body and in the cell wall. A mutant in the carboxyl-terminal region of the isopenicillin N acyltransferase lacking the three final amino acids of the enzymes was not properly located in the microbodies and failed to synthesize penicillin in vivo. In C. acremonium the genes involved in cephalosporin biosynthesis are separated in at least two clusters. Cluster I (pcbAB-pcbC) encodes the first two enzymes (alpha-aminoadipyl-cysteinyl valine synthetase and isopenicillin N synthase) of the cephalosporin pathway which are very similar to those involved in penicillin biosynthesis. Cluster I (cefEF-cefG), encodes the last three enzymatic activities (deacetoxycephalosporin C synthetase/hydroxylase and deacetylcephalosporin C acetyltransferase) of the cephalosporin pathway. It is unknown, atthis time, if the cefD gene encoding isopenicillin epimerase is linked to any of these two clusters. Methionine stimulates cephalosporin biosynthesis in cultures of three different strains of A. chrysogenum. Methionine increases the levels of enzymes (isopenicillin N synthase and deacetylcephalosporin C acetyltransferase) expressed from genes (pcbC and cefF respectively) which are separated in the two different clusters of cephalosporin biosynthesis genes. This result suggests that both clusters of genes have regulatory elements which are activated by methionine. Methionine-supplemented cells showed higher levels of transcripts of the pcbAB, pcbC, cefEF genes and to a lesser extent of cefF than cells grown in absence of methionine. The levels of the cefG transcript were very low as compared to those of pcbAB, pcbC and cefEF Theinduction by methionine of transcription of the four cephalosporin biosynthesis genes and the known effect of this amino acid on differentiation of A, chrysogenum indicates that methionine exerts a pleiotropiceffect that regulates coordinately cephalosporin biosynthesis and differentiation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 09:11:23