PP-binding proteins: modularity, scaffolding, and the modern polyketide frontier
🧪 lmctl-orchestrated review — written by an orchestrated team of AI agents, grounded in 1,917 papers from lmmol's literature graph. Citations link to their source on PubMed.
| Protein | Papers |
|---|---|
| Fatty acid synthase | 31 |
| Conidial pigment polyketide synthase alb1 | 25 |
| N-(5-amino-5-carboxypentanoyl)-L-cysteinyl-D-valine synthase | 20 |
| Nonribosomal peptide synthetase gliP | 20 |
| Enterobactin synthase component B | 17 |
| Fatty acid synthase | 16 |
| N-(5-amino-5-carboxypentanoyl)-L-cysteinyl-D-valine synthase | 16 |
| Enterobactin synthase component F | 16 |
PP-binding proteins anchor non-ribosomal and polyketide chemistry by carrying reactive carboxylate intermediates through repeated, domain-encoded steps. Across bacterial and fungal systems, the same phosphopantetheinyl chemistry appears as a reusable control point: changes in carrier loading and partner recognition can reroute flux, alter metabolite identity, and reshape ecological fitness phenotypes [1][2][3].
1. Domain architecture and catalytic logic
The core logic is now best framed as a programmable assembly grammar, where timing, docking, and substrate channeling are as important as raw enzymatic rate [4][PMID:276?][5]. Historical structural milestones established the modular polyketide synthase as a large, interlinked machine with repeated catalytic hand-offs [1][6], while carrier-domain studies showed how activation chemistry stays chemically conserved across systems but functionally diversified by local context [2].
2. What changed in the last few years
Recent comparative genetics and genomics have moved the conversation from descriptive cataloging toward mechanism-aware tractability: biosynthetic clusters are increasingly dissected as rewritable modules rather than rigid pathways, with repeated examples of gene-basket reconfiguration and cross-cluster recruitment [7][8]. In fungal systems especially, the integration of chromatin regulation and cluster-level transcriptional control is now interpreted as a major determinant of which carrier-dependent pathways become biochemically accessible in planta and under stress [9][10].
3. Emerging translation: drug discovery and host-pathogen ecology
A growing fraction of modern literature repositions PP-binding systems as intervention entry-points rather than static enzymology targets. In mycobacterial and actinomycete systems, polyketide and non-ribosomal assembly impacts virulence, metal capture, and immune escape in ways that are path- and context-specific [11][12][13]. This helps explain why carrier-domain architecture keeps reappearing in translational studies—from antibiotics to antifungal strategies—to the same family-level logic of substrate selectivity and chain-transfer control.
4. Practical takeaways for lmmol users
When scanning a PP-binding family, prioritize nodes that anchor shared subclusters rather than raw count frequency, because accessory loaders, docking proteins, and regulatory cofactors often determine phenotypic output [3][14]. In the literature graph, this tends to concentrate attention on a small cadre of high-studied hubs connected through conserved interaction neighborhoods, including acyl carrier and fatty-acid-linked systems [2][1].
References
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- Conti E., Stachelhaus T., Marahiel M.A., Brick P. Structural basis for the activation of phenylalanine in the non-ribosomal biosynthesis of gramicidin S. EMBO J 1997. PubMed 567×
- Donadio S., Staver M.J., McAlpine J.B., Swanson S.J. et al. Modular organization of genes required for complex polyketide biosynthesis. Science 1991. PubMed 700×
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- Broadhurst R.W., Nietlispach D., Wheatcroft M.P., Leadlay P.F. et al. The structure of docking domains in modular polyketide synthases. Chem. Biol 2003. PubMed 183×
- Khosla C., Tang Y., Chen A.Y., Schnarr N.A. et al. Structure and mechanism of the 6-deoxyerythronolide B synthase. Annu. Rev. Biochem 2007. PubMed 214×
- Lee J., Wu J., Deng Y., Wang J. et al. A cell-cell communication signal integrates quorum sensing and stress response. Nat. Chem. Biol 2013. PubMed 289×
- Drake E.J., Miller B.R., Shi C., Tarrasch J.T. et al. Structures of two distinct conformations of holo-non-ribosomal peptide synthetases. Nature 2016. PubMed 196×
- Bok J.W., Chiang Y.M., Szewczyk E., Reyes-Dominguez Y. et al. Chromatin-level regulation of biosynthetic gene clusters. Nat. Chem. Biol 2009. PubMed 285×
- Issartel J.P., Koronakis V., Hughes C. Activation of Escherichia coli prohaemolysin to the mature toxin by acyl carrier protein-dependent fatty acylation. Nature 1991. PubMed 263×
- De Voss J.J., Rutter K., Schroeder B.G., Su H. et al. The salicylate-derived mycobactin siderophores of Mycobacterium tuberculosis are essential for growth in macrophages. Proc. Natl. Acad. Sci. U.S.A 2000. PubMed 450×
- Tsai H.F., Chang Y.C., Washburn R.G., Wheeler M.H. et al. The developmentally regulated alb1 gene of Aspergillus fumigatus: its role in modulation of conidial morphology and virulence. J. Bacteriol 1998. PubMed 263×
- Boehnert H.U., Fudal I., Dioh W., Tharreau D. et al. A putative polyketide synthase/peptide synthetase from Magnaporthe grisea signals pathogen attack to resistant rice. Plant Cell 2004. PubMed 232×
- Kuhajda F.P., Jenner K., Wood F.D., Hennigar R.A. et al. Fatty acid synthesis: a potential selective target for antineoplastic therapy. Proc. Natl. Acad. Sci. U.S.A 1994. PubMed 594×