Volume 16 Issue 4, April 2020

Phospholipase D (PLD) regulates various cellular functions through the signaling lipid phosphatidic acid (PA). New crystal structures of human PLD1 and PLD2 reveal a catalytic mechanism, inhibitor binding, and regulation, enabling future structure-based inhibitor design and functional studies of PLD.

Tyrosine sulfation is a common post-translational modification known to play critical roles in multiple bioprocesses. A cleverly engineered mammalian expanded genetic code now enables the direct co-translational incorporation of tyrosine sulfates into proteins to study their function in cellular contexts.

The mechanisms by which bioactive drugs get into their target cells is a question that has been greatly neglected. A new survey with CRISPR–Cas9 shows the widespread importance of protein transporters called solute carriers (SLCs).

This Perspective describes the chemical and biophysical principles common to all bifunctional, proximity-inducing small molecules. It also discusses the underappreciated diversity of their chemical structures and biological mechanisms.

The authors used an expanded genetic code to incorporate sulfated tyrosine into specific sites of proteins expressed in E. coli and mammalian cells and showed that sulfation of tyrosine at different sites had different functions.

Structural and mutational analysis of three homologous cyclases involved in the biosynthesis of iboga and aspidosperma alkaloids reveals how they convert a common substrate into three distinct scaffolds by controlling regio- and stereoselectivity.

A simple and effective strategy is introduced to increase CRISPR–Cas9-mediated gene knock-in rates by using 5′-modified double-stranded DNA donors with short homology arms.

Crystal structures of phospholipase hPLD1 and hPLD2 catalytic domains and an analysis of the binding modes of dual and isoform-selective inhibitors define mechanisms of PLD regulation and catalytic activity.

A structural study of one of two human phospholipase D enzymes, hPLD1, helps define the determinants of substrate recognition, the highly regulated enzymatic activity, as well as activation by PIP₂ and RhoA.

HIDE probes were developed for long time-lapse imaging of endolysosomes and their dynamics at super-resolution. These probes enabled analyses of endosome motility in primary fibroblasts from patients with Niemann–Pick C with distinct mutations in NPC1.

Certain cyanobacteria use an alternative biotin biosynthetic pathway that replaces BioA with the dehydrogenase BioU, a suicide enzyme that catalyzes its reaction via conjugation to Lys124 and loses the amino group of this residue in the process.

Designed heterotrimers of collagen I, locked in three possible chain registers, enable structural and functional characterization of each permutation, leading to identification of the AAB heterotrimer as the most active and therefore likely to occur biologically.

NMR structural analysis of an active state of the β₂-adrenergic receptor defines a unique orientation for the intracellular half of TM6, responsible for G-protein binding, including an equilibrium among three conformations of a key microswitch.

The authors utilize fluorescence-activated cell sorting coupled with next-generation sequencing, as well as dynamic modeling, to study the molecular mechanism underlying indole signaling and reveal different roles of the two ends of tnaC in coordinating transcription and translation.

Structural characterization of WbbM, an enzyme involved in O2a-antigen biosynthesis in Klebsiella pneumoniae, reveals two unique active sites with galactopyranosyl- or galactofuranosyl-transferase activities for oligosaccharide polymerization.

An improved workflow combining de novo transcriptome assembly and Ribo-seq validated by cellular antigen display is developed to maximize small peptide discovery, leading to identification of thousands of unannotated protein-coding smORFs.

A set of CRISPR–Cas9-based genetic screens in a haploid human cell line identifies more than 200 gene–drug associations involving solute carriers (SLCs), transporters important for the uptake and activity of cytotoxic drugs.