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Co-transcriptional cleavage and transcription termination are closely related processes during mRNA maturation, yet their coordination remains poorly understood due to difficulties in detecting these transient events. Here, we applied single-molecule nascent RNA sequencing to simultaneously capture the cleavage status and readthrough distance on the same nascent RNA molecules and characterize 14 mutants of various pre-mRNA processing factors in Arabidopsis.Our results reveal diverse roles for these processing factors in coordinating cleavage and termination: core components of CPSF and CstF complex stimulate both cleavage and termination, facilitating access to exoribonuclease AtXRN3; mutations in nuclear poly(A) polymerase PAPS1 and AtXRN3 caused delayed termination with minimal effects on cleavage, suggesting their roles are further downstream; BORDER proteins facilitate termination while simultaneously inhibiting cleavage, suggesting a complex interplay between these two actions; the phosphatase SSU72 specifically promotes efficient termination without affecting cleavage. Our method also enables us to distinguish cleaved readthrough transcripts from full-length readthrough, and we found termination factor FPA specifically promotes termination of cleaved readthrough, suggesting FPA facilitates access of AtXRN3 to the 3’ cleavage product. Our comprehensive datasets reveal cleavage and termination are highly coordinated during pre-mRNA processing. 

Polystyrene (PS) is one of the most used, yet infrequently recycled plastics. Although manufactured on the scale of 300 million tons per year globally, current approaches toward PS degradation are energy- and carbon-inefficient, slow, and/or lim- ited in the value that they reclaim. We recently reported a scalable process to degrade post-consumer polyethylene-containing waste streams into carboxylic diacids. Engineered fungal strains then upgrade these diacids biosynthetically to synthesize pharmacologi- cally active secondary metabolites. Herein, we apply a similar reaction to rapidly convert PS to benzoic acid in high yield. Engi- neered strains of the filamentous fungus Aspergillus nidulans then biosynthetically upgrade PS-derived crude benzoic acid to the structurally diverse secondary metabolites ergothioneine, pleuromutilin, and mutilin. Further, we expand the catalog of plastic- derived products to include spores of the industrially relevant biocontrol agent Aspergillus flavus Af36 from crude PS-derived ben- zoic acid. 

The gyroscope like dichloride complexes trans -Pt(Cl) 2 (P((CH 2 ) n ) 3 P) ( trans -2; n = c, 14; e, 18; g, 22) and MeLi (2 equiv.) react to yield the parachute like dimethyl complexes cis -Pt(Me) 2 (P((CH 2 ) n ) 3 P) ( cis -4c,e,g, 70–91%). HCl (1 equiv.) and cis -4c react to give cis -Pt(Cl)(Me)(P((CH 2 ) 14 ) 3 P) ( cis -5c, 83%), which upon stirring with silica gel or crystallization affords trans -5c (89%). Similar reactions of HCl and cis -4e,g give cis / trans -5e,g mixtures that upon stirring with silica gel yield trans -5e,g. A parallel sequence with trans -2c/EtLi gives cis -Pt(Et) 2 (P((CH 2 ) 14 ) 3 P) ( cis -6c, 85%) but subsequent reaction with HCl affords trans -Pt(Cl)(Et)(P((CH 2 ) 14 ) 3 P) ( trans -7c, 45%) directly. When previously reported cis -Pt(Ph) 2 (P((CH 2 ) 14 ) 3 P) is treated with HCl (1 equiv.), cis - and trans -Pt(Cl)(Ph)(P((CH 2 ) 14 ) 3 P) are isolated (44%, 29%), with the former converting to the latter at 100 °C. Reactions of trans -5c and LiBr or NaI afford the halide complexes trans -Pt(X)(Me)(P((CH 2 ) 14 ) 3 P) ( trans -9c, 88%; trans -10c, 87%). Thermolyses and DFT calculations that include acyclic model compounds establish trans > cis stabilities for all except the dialkyl complexes, for which energies can be closely spaced. The σ donor strengths of the non-phosphine ligands are assigned key roles in the trends. The crystal structures of cis -4c, trans -5c, trans -7c, and trans -10c are determined and analyzed together with the computed structures.