Non-ribosomal peptide synthetases are assembly line biosynthetic pathways that are used to produce critical therapeutic drugs and are typically arranged as large multi-domain proteins called megasynthetases. They synthesize polypeptides using peptidyl carrier proteins that shuttle each amino acid through modular loading, modification and elongation steps, and remain challenging to structurally characterize, owing in part to the inherent dynamics of their multi-domain and multi-modular architectures. Here we have developed site-selective crosslinking probes to conformationally constrain and resolve the interactions between carrier proteins and their partner enzymatic domains.
View Article and Find Full Text PDFBackground: Glyoxal has been implicated as a significant contributor to the formation of secondary organic aerosols, which play a key role in our ability to estimate the impact of aerosols on climate. Elevated concentrations of glyoxal over open ocean waters suggest that there exists an additional source, different from urban and forest environments, which has yet to be identified.
Methods: Based on mass spectrometric analyses of nascent sea spray aerosols (SSAs) and gas-phase molecules generated during the course of a controlled algal bloom, the work herein suggests that marine microorganisms are capable of excreting toluene in response to environmental stimuli.
The first search for soft unclustered energy patterns (SUEPs) is performed using an integrated luminosity of 138 fb^{-1} of proton-proton collision data at sqrt[s]=13 TeV, collected in 2016-2018 by the CMS detector at the LHC. Such SUEPs are predicted by hidden valley models with a new, confining force with a large 't Hooft coupling. In events with boosted topologies, selected by high-threshold hadronic triggers, the multiplicity and sphericity of clustered tracks are used to reject the background from standard model quantum chromodynamics.
View Article and Find Full Text PDFCarrier protein-dependent synthases are ubiquitous enzymes involved both in primary and secondary metabolism. Biocatalysis within these synthases is governed by key interactions between the carrier protein, substrate, and partner enzymes. The weak and transient nature of these interactions has rendered them difficult to study.
View Article and Find Full Text PDF