PMID:8344300

Citation	Alvarez, E, Meesschaert, B, Montenegro, E, Gutiérrez, S, Díez, B, Barredo, JL and Martín, JF (1993) The isopenicillin-N acyltransferase of Penicillium chrysogenum has isopenicillin-N amidohydrolase, 6-aminopenicillanic acid acyltransferase and penicillin amidase activities, all of which are encoded by the single penDE gene. Eur. J. Biochem. 215:323-32
Abstract	The isopenicillin-N acyltransferase of Penicillium chrysogenum catalyzes the conversion of the biosynthetic intermediate isopenicillin N to the hydrophobic penicillins. The isopenicillin-N acyltransferase copurified with the acyl-CoA:6-aminopenicillanic acid (6-APA) acyltransferase activity which transfers an acyl residue from acyl-CoA derivatives (e.g. phenylacetyl-CoA, phenoxyacetyl-CoA) to 6-APA. Other thioesters of phenylacetic acid were also used as substrates. An amino acid sequence similar to that of the active site of thioesterases was found in the isopenicillin-N acyltransferase, suggesting that this site is involved in the transfer of phenylacetyl residues from phenylacetyl thioesters. Purified isopenicillin-N acyltransferase also showed isopenicillin-N amidohydrolase, penicillin transacylase and penicillin amidase activities. The isopenicillin-N amidohydrolase (releasing 6-APA) showed a much lower specific activity than the isopenicillin-N acyltransferase of the same enzyme preparation, suggesting that in the isopenicillin-N acyltransferase reaction the 6-APA is not released and is directly converted into benzylpenicillin. Penicillin transacylase exchanged side chains between two hydrophobic penicillin molecules; or between one penicillin molecule and 6-APA. The penicillin amidase activity is probably the reverse of the biosynthetic acyl-CoA:6-APA acyltransferase. Four P. chrysogenum mutants deficient in acyl-CoA:6-APA acyltransferase lacked the other four related activities. Transformation of these mutants with the penDE gene restored all five enzyme activities.
Links	PubMed
Keywords	Acyltransferases/genetics; Acyltransferases/isolation & purification; Acyltransferases/metabolism; Amidohydrolases/isolation & purification; Amidohydrolases/metabolism; Amino Acid Sequence; Culture Media; Dithiothreitol/pharmacology; Electrophoresis, Polyacrylamide Gel; Enzyme Induction/drug effects; Gene Expression; Molecular Sequence Data; Mutation; Penicillin Amidase/genetics; Penicillin Amidase/isolation & purification; Penicillin Amidase/metabolism; Penicillin-Binding Proteins; Penicillins/metabolism; Penicillium chrysogenum/enzymology; Penicillium chrysogenum/genetics; Substrate Specificity; Sulfhydryl Reagents/pharmacology
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
PENCH:AAAA	Contributes to	GO:0050640: isopenicillin-N N-acyltransferase activity	ECO:0000314:		F		Responsible for isopenicillin-N amidohydrolase, 6-aminopenicillanic acid acyltransferase and penicillin amidase activities in P. chrysogenum. Mutants npe6, npe8 and npe10 with no acyltransferase activity were transformed with a plamsid, pULB101, containing penDE gene. Mutants were then prepared and assayed. Npe6, npe8 and npe10 showed AAT, IAT, IPN amidohydrolase, penicillin transacylase and penicllin amidase activities. This indicated the penDE gene recovered all acyltransferase activity. Table 6 shows the results of an assay for the comparison between P. chrysogenum and C. acremonium. C. acremonium does not contain the penDE gene and recorded zero activity for Acyl-CoA:CAPA acyltransferase activity, extracellular accumulation of 6-APA, and production of penicillin. Whereas, P. chrysogenum does contain the penDE gene and showed positive results for these activities.	complete CACAO 4068

References

See Help:References for how to manage references in GONUTS.