A Single Sfp-Type Phosphopantetheinyl Transferase Plays a Major Role in the Biosynthesis of PKS and NRPS Derived Metabolites in Streptomyces ambofaciens ATCC23877

Abstract

The phosphopantetheinyl transferases (PPTases) are responsible for the activation of the carrier protein domains of the polyketide synthases (PKS), non ribosomal peptide synthases (NRPS) and fatty acid synthases (FAS). The analysis of the Streptomyces ambofaciens ATCC23877 genome has revealed the presence of four putative PPTase encoding genes. One of these genes appears to be essential and is likely involved in fatty acid biosynthesis. Two other PPTase genes, samT0172 (alpN) and samL0372, are located within a type II PKS gene cluster responsible for the kinamycin production and an hybrid NRPS-PKS cluster involved in antimycin production, respectively, and their products were shown to be specifically involved in the biosynthesis of these secondary metabolites. Surprisingly, the fourth PPTase gene, which is not located within a secondary metabolite gene cluster, appears to play a pleiotropic role. Its product is likely involved in the activation of the acyl- and peptidyl-carrier protein domains within all the other PKS and NRPS complexes encoded by S. ambofaciens. Indeed, the deletion of this gene affects the production of the spiramycin and stambomycin macrolide antibiotics and of the grey spore pigment, all three being PKS-derived metabolites, as well as the production of the nonribosomally produced compounds, the hydroxamate siderophore coelichelin and the pyrrolamide antibiotic congocidine. In addition, this PPTase seems to act in concert with the product of samL0372 to activate the ACP and/or PCP domains of the antimycin biosynthesis cluster which is also responsible for the production of volatile lactones.

New Insights into Chloramphenicol Biosynthesis in Streptomyces venezuelae ATCC 10712

“…Sven0914 contains all of the conserved motifs found in the F/KES subfamily of Sfp-type PPTases ( 30 , 31 ). While many members of this subfamily utilize PCPs as substrates, there are exceptions, most notably the Sco6673-like PPTase of Streptomyces ambofaciens , which is able to accept both ACP and PCP domains as substrates ( 32 ) and which shares 53% amino acid sequence identity with Sven0914. Consequently, we cannot reliably predict whether Sven0914 is involved in the modification of the PCP domain of Sven0922 (see below), the ACP Sven0929, or both.…”

Lincosamide Synthetase—A Unique Condensation System Combining Elements of Nonribosomal Peptide Synthetase and Mycothiol Metabolism

“…The additional identified protein indirectly involved in the NDLS function of lincomycin biosynthesis is Slp from S. lincolnensis , a PPTase converting the apo -LmbN-CP to the active holo -form with a phosphopantetheine cofactor bound. Generally the PPTases involved in secondary metabolism can be encoded either directly in the respective biosynthetic gene cluster [ 33 , 43 , 44 ] or somewhere else in the genome [ 35 , 45 , 46 ] as is the case of Slp. According to the sequence homology, the identified Slp protein belongs to F/KES subfamily of Sfp-type PPTases [ 47 ].…”

Paenibacillus polymyxa A26 Sfp-type PPTase inactivation limits bacterial antagonism against Fusarium graminearum but not of F. culmorum in kernel assay

“…What mechanism could explain the different effect of the mutant strain in the kernel assay? The Sfp-type PPTase activates peptidyl carrier protein domains ( Quadri et al, 1998 ; Beld et al, 2014 ; Bunet et al, 2014 ). During the compound assembly, the biosynthesis intermediates are attached to carrier protein domains of NRPS and PKS via a phosphopantetheinyl arm.…”