Research articles

Validation of the cellular targets of microRNAs remains an ongoing priority. miR-CLIP, a new method based on psoralen crosslinking, immunoprecipitation and biotin affinity pulldowns, was applied to determine the miR-106a targetome, which included the H19 lncRNA.

Genetic evidence suggested jamABC from the jamaicamide biosynthetic pathway were responsible for the synthesis of the terminal alkyne functional group. Biochemical studies now confirm this activity and demonstrate the insertion of alkynes into two unrelated natural products.

Disulfide trapping and FRET studies define an agonist-induced conformational change in mGlu2 from inactive symmetric dimers with an interface at transmembrane domains (TMs) 4 and 5 to an active state with TM6s serving as the dimer interface.

Biocatalysis can take advantage of an enzyme's inherent reactivity regardless of its physiological role, as shown for a terpene cyclase turned Brønsted acid catalyst after its active site pocket was mutated while the activated aspartic acid was retained.

Characterization of four enzymes involved in biosynthesis of the plant metabolite and anticancer agent noscapine completes this pathway and identifies an unusual acetyl protecting group strategy that defines the order of enzymatic steps.

A family of cyclic lipopeptide natural products named lysocins was isolated from a soil bacteria sample and was found to exhibit antimicrobial actions. Genetic and biochemical evidence showed that lysocin E targets bacterial menaquinone.

An NMR structure reveals that the C terminus of the ubiquitin-conjugating enzyme Ube2w is disordered, leading to specific pairings with disordered substrates; loss of this sequence causes decreased substrate binding and ubiquitin transfer activity.

Inhibitors of FKBP51 with antidepressive activity are selective over the related FKBP52 and bind FKBP51 by an induced-fit mechanism that causes a conformational change. The analogous conformational change in FKBP52 generates a strained conformation.

A redox relay was identified in mammalian cells where the H₂O₂-reactive protein peroxiredoxin-2 oxidizes the transcription factor STAT3, resulting in the formation of transcriptionally inactive disulfide-linked oligomers.

Peptide natural product backbones are typically made ribosomally or by NRPS machinery. Exploration of pheganomycin biosynthesis defines a third hybrid model in which a grasp ligase joins an NRPS product with a ribosomally produced peptide.

The structure of complement regulatory protein factor H in complex with a preferred sialylated trisaccharide and the C3b thioester domain supports the idea of a ternary complex that mediates discrimination between self and nonself in a branch of innate immunity.

PimA provides an unusual example of conformational flexibility: structural, biophysical and disulfide trapping experiments now show a glycosyltransferase involved in tuberculosis virulence undergoes a major rearrangement upon contact with membranes.

Bacterial MreB forms cytoskeletal filaments, rotating around the cell width, helping to shape cells. Imaging experiments indicate that MreB association with the B. subtilis cell membrane requires the peptidoglycan and wall teichoic acid precursor lipid II.

Biochemical, bioinformatic and genetic evidence uncover a tyrosine biosynthesis pathway in plants that—in contrast to known plant pathways—occurs in the cytosol, is insensitive to tyrosine feedback regulation and uses the traditionally bacterial prephenate dehydrogenase.

The loss of GSK-3 activity alters cellular responsiveness to kinase inhibitors such as mTOR and PLK1. A kinome-wide RNAi screen reveals that GSK-3 interacts with a third of known kinases.

A crystal structure of a chimera composed of lipid-metabolizing transmembrane enzymes HRASLS3 and LRAT (which catalyzes esterification of vitamin A) identifies a quaternary structural rearrangement that coincides with formation of a three-dimensionally swapped dimer.

Proteolysis must be carefully controlled to degrade desired targets without causing cellular damage. New data show that Lon protease in Enterobacteriaceae is regulated by a redox-dependent disulfide bond that determines the size of its exit pore.

The α1-adrenergic receptor antagonist terazosin protects flies and mammalian cells from stress and apoptosis through direct activation of the glycolytic enzyme phosphoglycerate kinase 1, which interacts with Hsp90 to promote ATP consumption.

Diels-Alder chemistry is widely used for bioconjugations, and one variant of the reaction can ‘deprotect’ a small molecule via spontaneous elimination. This activation chemistry is now demonstrated on biomolecules in cells at high yields in 10 minutes.

Increasing residual helicity in the p53 transcriptional activation domain strengthened interactions with Mdm2, resulting in alterations in p53 protein dynamics, impaired transcription of target genes and failure to promote cell cycle arrest.