Dormant tie reactivation as an affiliative coping response to stressors during the COVID-19 crisis.

This study takes an affiliative coping theory perspective to examine whether working adults reactivated dormant ties with individuals they had not contacted for at least 3 years to cope with stressors experienced due to the COVID-19 pandemic. Stressors originating in the workplace (job insecurity and remote work) and in the family (stressful familial social ties) were examined in a sample of 232 working adults in the southeastern United States. Individuals were more likely to reactivate their dormant ties when their job was insecure, and the magnitude of the reactivations was greater among individuals experiencing stressful social ties with family members than those not experiencing those stressors.

Tuning Catalytic Bias of Hydrogen Gas Producing Hydrogenases.

Hydrogenases display a wide range of catalytic rates and biases in reversible hydrogen gas oxidation catalysis. The interactions of the iron-sulfur-containing catalytic site with the local protein environment are thought to contribute to differences in catalytic reactivity, but this has not been demonstrated. The microbe produces three [FeFe]-hydrogenases that differ in "catalytic bias" by exerting a disproportionate rate acceleration in one direction or the other that spans a remarkable 6 orders of magnitude.

The crystal structure of dGTPase reveals the molecular basis of dGTP selectivity.

Deoxynucleotide triphosphohydrolases (dNTPases) play a critical role in cellular survival and DNA replication through the proper maintenance of cellular dNTP pools. While the vast majority of these enzymes display broad activity toward canonical dNTPs, such as the dNTPase SAMHD1 that blocks reverse transcription of retroviruses in macrophages by maintaining dNTP pools at low levels, ()dGTPase is the only known enzyme that specifically hydrolyzes dGTP. However, the mechanism behind dGTP selectivity is unclear.

Critical Role of Water Molecules in Proton Translocation by the Membrane-Bound Transhydrogenase.

The nicotinamide nucleotide transhydrogenase (TH) is an integral membrane enzyme that uses the proton-motive force to drive hydride transfer from NADH to NADP in bacteria and eukaryotes. Here we solved a 2.2-Å crystal structure of the TH transmembrane domain (Thermus thermophilus) at pH 6.

Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography.

X-ray free-electron lasers (XFELs) provide very intense X-ray pulses suitable for macromolecular crystallography. Each X-ray pulse typically lasts for tens of femtoseconds and the interval between pulses is many orders of magnitude longer. Here we describe two novel acoustic injection systems that use focused sound waves to eject picoliter to nanoliter crystal-containing droplets out of microplates and into the X-ray pulse from which diffraction data are collected.