Genetic characterization of pcpS, encoding the multifunctional phosphopantetheinyl transferase of Pseudomonas aeruginosa

Abstract

Fatty acid synthases (primary metabolism), non-ribosomal peptide synthases and polyketide synthases (secondary metabolism) contain phosphopantetheinyl (Ppant)-dependent carrier proteins that must be made functionally active by transfer of the 49-Ppant moiety from coenzyme A. These reactions are usually catalysed by dedicated Ppant transferases. Although rich in Ppant-dependent carrier proteins, it was previously shown that Pseudomonas aeruginosa possesses only one Ppant transferase, encoded by pcpS, which functions in both primary and secondary metabolism. Consistent with this notion are our findings that pcpS can genetically complement mutations in the Escherichia coli acpS and entD genes, encoding the apo-acyl carrier protein (ACP) synthase of fatty acid synthesis and a Ppant transferase of enterobactin synthesis, respectively. It also complements a Bacillus subtilis sfp mutation affecting a gene encoding a Ppant transferase essential for surfactin synthesis. A pcpS insertion mutant could only be constructed in a strain carrying the E. coli acpS gene on a chromosomally integrated element in trans, implying that the in vitro essentiality of pcpS is due to its requirement for activation of apo-ACP of fatty acid synthesis. The conditional pcpS mutant is non-fluorescent, does not produce pyoverdine and pyochelin, and does not grow in the presence of iron chelators. The data presented here for the first time confirm that PcpS plays an essential role in both fatty acid and siderophore metabolism.

Evidence for a novel phosphopantetheinyl transferase domain in the polyketide synthase for enediyne biosynthesis

“…The domain boundaries (1707-1919 aa) for the PPTase domain were initially determined by sequence alignment with type II PPTases [19,20]. The purified PPTase domain protein contains 213 residues and is referred as PPTase1 (Fig.…”

A Sfp-type phosphopantetheinyl transferase ZmsO is essential for zeamines production and the virulence of Dickeya zeae

“…For example, PPTase is essential for the production of mupirocin in P. fluorescens (Shields et al 2010), erythromycin in Saccharopolyspora erythraea (Weissman et al 2004), fatty acid in E. coli strain O157:H7 (Lay and Lay and Cronan 2006), both fatty acid and siderophore in P. aeruginosa (Barekzi et al 2004) and for the biosynthesis of virulence factors in Mycobacterium (Chalut et al 2006). Identification of the role of ZmsO in zeamines production adds a new member to the list of PPTases which are associated with the biosynthesis of secondary metabolites with biological significances.…”

Two Bacterial Group II Phosphopantetheinyl Transferases Involved in Both Primary Metabolism and Secondary Metabolism

“…Recently, it has been reported that Sppt and Hppt phosphopantetheinylate ACPs involved in primary metabolism [18,22]; PPT Ns phosphopantetheinylates ACPs and PCPs involved in secondary metabolism [4]; PcpS phosphopantetheinylates ACPs and PCPs involved in both primary metabolism and secondary metabolism [1]. In this study, we characterized the specificities of Hppt and Sppt and the effects of their N/C terminus to the activities.…”

“…Few bacteria contain only one group II PPTase, which should be involved in both primary metabolism and secondary metabolism in the absence of group I PPTase, such as PcpS in Pseudomonas aeruginosa [1], PPT Ns in Nodularia spumigena NSOR10 [4], Sppt in Synechocystis sp. PCC6803 [18], and Hppt in Haemophilus influenza.…”