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Weir, A.

Publications and source records attributed to Weir, A..

2 recordsLinked to original sources

Benchmarking siRNA Prediction: The Role of Representation and Validation Strategies

Small interfering RNAs (siRNAs) offer transformative potential for targeted therapeutics, yet the design of highly effective and non-toxic candidates is hindered by the risk of off-target effects and RNA instability. A critical flaw in in silico prediction models is pervasive data leakage in cross-validation protocols, which artificially inflates performance metrics and produces untrustworthy results. To address this, we developed a rigorous framework that eliminates data leakage through strict cross-validation, leverages z-curves (3D representations of RNA physico-chemical properties) for context-aware sequence encoding, and identifies key sequence regions critical for efficacy. Our model achieves an AUC of 0.845 on leakage-free validation, surpassing prior work at 380x faster computation speed, demonstrating that superior representation trumps model complexity. Crucially, we demonstrate how experimental variability and cross-validation choices directly impact model reliability, establishing the first benchmarked methods for robust siRNA efficacy prediction. This work provides a foundation for trustworthy sequence design and validation in RNA therapeutics.

bioinformatics↗

Charting the biosynthetic landscape of hybrid polyketide-nonribosomal peptide-specialized lipids

Polyunsaturated fatty acid (PUFA) synthase-like enzymes are best known for their role in membrane lipid biosynthesis in marine bacteria, but have also been repurposed for the assembly of specialized lipid metabolites with unique biological functions. Here, we illuminate their broader biosynthetic potential by charting the unexplored landscape of hybrid peptide-polyketide-specialized lipid biosynthesis in bacteria. Using a targeted genome mining strategy, we identified more than 60 biosynthetic gene clusters that combine PUFA synthase-like, polyketide synthase (PKS), and nonribosomal peptide synthetase (NRPS) enzymes across diverse bacterial lineages. Comparative analysis revealed extensive diversification of these triple hybrid pathways through gene fusion, domain reshuffling and recruitment of accessory enzymes. We further expand the known repertoire of peptide-polyketide-specialized lipid hybrids by identifying the chitinimines, a new family of amphiphilic metabolites produced by Chitinimonas koreensis featuring a C22 polyunsaturated lipid chain conjugated to a cyclic peptide-polyketide and a pyruvate-derived cyclic acetal moiety. The chitinimines exhibit surfactant properties, as well as moderate antibacterial activity against Gram-positive bacteria and contribute to a growth-promoting interaction between C. koreensis and Salmonella spp. Together, these findings demonstrate that PUFA synthase-like systems are far more versatile than previously appreciated, playing a key role in combinatorial biosynthetic innovation and serving as a rich, untapped source of chemically and functionally diverse specialized lipids.

microbiology↗