Post-translational enzyme modification by the phosphopantetheinyl transferase is required for lysine and penicillin biosynthesis but not for roquefortine or fatty acid formation in Penicillium chrysogenum

Abstract

NRPSs (non-ribosomal peptide synthetases) and PKSs (polyketide synthases) require post-translational phosphopantetheinylation to become active. This reaction is catalysed by a PPTase (4'-phosphopantetheinyl transferase). The ppt gene of Penicillium chrysogenum, encoding a protein that shares 50% similarity with the stand-alone large PPTases, has been cloned. This gene is present as a single copy in the genome of the wild-type and high-penicillin-producing strains (containing multiple copies of the penicillin gene cluster). Amplification of the ppt gene produced increases in isopenicillin N and benzylpenicillin biosynthesis. A PPTase-defective mutant (Wis54-PPT(-)) was obtained. It required lysine and lacked pigment and penicillin production, but it still synthesized normal levels of roquefortine. The biosynthesis of roquefortine does not appear to involve PPTase-mediated modification of the synthesizing enzymes. The PPT(-) mutant did not require fatty acids, which indicates that activation of the fatty acid synthase is performed by a different PPTase. Complementation of Wis54-PPT(-) with the ppt gene restored lysine biosynthesis, pigmentation and penicillin production, which demonstrates the wide range of processes controlled by this gene.

The molecular and genetic basis of conidial pigmentation in Aspergillus niger

“…niger DpptA produces nearly white conidia and no secondary metabolites of polyketide or non-ribosomal peptide origin. These phenotypes are very like those described for the same genotype in A. nidulans (Márquez-Fernández et al, 2007;Oberegger et al, 2003;Keszenman-Pereyra et al, 2003), as well as for Penicillium chrysogenum (García-Estrada et al, 2008) and Colletrotrichum graminicola (Horbach et al, 2009). The significant residual fawn pigmentation of the DfwnA has not been described for disruptants of orthologous genes in other Aspergilli, in which the resulting phenotype is white.…”

Degeneration of penicillin production in ethanol-limited chemostat cultivations of Penicillium chrysogenum: A systems biology approach

“…Furthermore impairment of post translational modification could result in the production of non-functional protein. ACVS requires post-translational phosphopantetheinylation to become active [43]. This reaction is catalyzed by a PPTase (4'-phosphopantetheinyl transferase).…”

Penicillins and Cephalosporins

“…These genes are arranged in a single cluster located in a DNA region present as a single copy in the genome of the wild-type NRRL 1951 and Wisconsin 54-1255 strains (laboratory reference strain), but that is amplified in tandem repeats in penicillin-overproducing strains [16]. The phlA gene encoding the phenylacetyl-CoA ligase and the ppt gene encoding the PPTase, which activates the ACVS, are not located in the amplified region [13,25]. Many of the improved penicillin producers contain several copies of the amplified region, such as the E1, which contains 12-14 copies.…”

“…In addition to this, the advances in genetics and molecular biology have allowed researchers to engineer P. chrysogenum strains in order to introduce punctual modifications with a positive effect on the penicillin titers. The increase in penicillin production has been related to the overexpression of different genes, such as the ppt gene encoding PPTase [25], or the laeA gene encoding the secondary metabolism global regulator PcLaeA [19].…”