Phosphorothioate nucleotides have emerged as powerful pharmacological substitutes of their native phosphodiester analogs with important translational applications in antisense oligonucleotide (ASO) therapeutics and cyclic dinucleotide (CDN) synthesis. Stereocontrolled installation of this chiral motif has long been hampered by the systemic use of phosphorus(III) [P(III)]-based reagent systems as the sole practical means of oligonucleotide assembly. A fundamentally different approach is described herein: the invention of a P(V)-based reagent platform for programmable, traceless, diastereoselective phosphorus-sulfur incorporation. The power of this reagent system is demonstrated through the robust and stereocontrolled synthesis of various nucleotidic architectures, including ASOs and CDNs, via an efficient, inexpensive, and operationally simple protocol.

Most protein kinases share a DFG (Asp-Phe-Gly) motif in the ATP site which can assume two distinct conformations, the active DFG-in and the inactive DFG-out states. Small molecule inhibitors able to induce the DFG-out state have received considerable attention in kinase drug discovery. Using a typical DFG-in inhibitor scaffold of Aurora A, a kinase involved in the regulation of cell division, we found that halogen and nitrile substituents directed at the N-terminally flanking residue Ala273 induced global conformational changes in the enzyme, leading to DFG-out inhibitors that are among the most potent Aurora A inhibitors reported to date. The data suggest an unprecedented mechanism of action, in which induced-dipole forces along the Ala273 side chain alter the charge distribution of the DFG backbone, allowing the DFG to unwind. As the ADFG sequence and three-dimensional structure is highly conserved, DFG-out inhibitors of other kinases may be designed by specifically targeting the flanking alanine residue with electric dipoles.

Oomycete pathogens secrete host cell-entering effector proteins to manipulate host immunity during infection. We previously showed that PsAvh52, an early-induced RxLR effector secreted from the soybean root rot pathogen, Phytophthora sojae, could suppress plant immunity. Here, we found that PsAvh52 is required for full virulence on soybean and binds to a novel soybean transacetylase, GmTAP1, in vivo and in vitro. PsAvh52 could cause GmTAP1 to relocate into the nucleus where GmTAP1 could acetylate histones H2A and H3 during early infection, thereby promoting susceptibility to P. sojae. In the absence of PsAvh52, GmTAP1 remained confined to the cytoplasm and did not modify plant susceptibility. These results demonstrate that GmTAP1 is a susceptibility factor that is hijacked by PsAvh52 in order to promote epigenetic modifications that enhance the susceptibility of soybean to P. sojae infection.

Background:MurA is critical for the biosynthesis of the bacterial cell wall. Results: The covalent MurA-phosphoenolpyruvate adduct was captured in different reaction states. Conclusion: The covalent adduct primes phosphoenolpyruvate for catalysis and enables feedback inhibition by UDP-N-acetylmuramic acid, the product of MurB. Significance: Cellular MurA exists in a previously unrecognized and tightly locked complex, which presumably accounts for the failure of drug discovery efforts.