Catálogo de publicaciones - revistas

<jats:title>How to stop RNA polymerase</jats:title> <jats:p> Timely and tunable cessation of RNA synthesis is vital for cellular homeostasis. RNA helicases such as the archetypal termination factor r actively dismantle transcription complexes, but the transitory nature of termination makes the process hard to study structurally. Said <jats:italic>et al.</jats:italic> assembled ρ-bound transcription complexes and studied them using cryo–electron microscopy with an approach that captured a series of functional states en route to termination. They found an extensive and dynamic network of r interactions with RNA polymerase, nucleic acids, and accessory Nus factors. ρ mediates stepwise rearrangements of these contacts, transforming an actively transcribing complex into a moribund pretermination intermediate. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6524" page="eabd1673" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abd1673">44</jats:related-article> </jats:p>

<jats:title>Anticoagulants take over</jats:title> <jats:p> In its fully reduced form, vitamin K helps to catalyze an oxidation reaction essential for blood coagulations, but it must be regenerated in each reaction through reduction. Liu <jats:italic>et al.</jats:italic> determined the structures of the enzyme responsible, vitamin K epoxide reductase, bound to an oxidized vitamin K substrate or with anticoagulants, including the widely prescribed drug warfarin. Understanding how these molecules bind and inhibit explains some variations in the therapeutic response as well as resistance for anticoagulants used in pest control. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6524" page="eabc5667" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abc5667">43</jats:related-article> </jats:p>

<jats:title>Doubts in cancer-rhythms connections</jats:title> <jats:p>Circadian clocks help to coordinate physiological processes with the daily cycles of light and dark and periods of feeding, activity, and rest. Being out of sync with such 24-hour cycles can have unhealthy effects. Sancar and Van Gelder review the available evidence regarding circadian disruption and predisposition to cancer and circadian variations in response to cancer chemotherapy. The literature can be difficult to interpret. For example, complete knockouts of clock genes are not the same as shift work. Overall, they find that the jury is still out on whether circadian disruption can promote cancer in general and if the timing of cancer treatment can be optimized. However, enough indications are present that further research is recommended.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6524" page="eabb0738" related-article-type="in-this-issue" vol="371" xlink:href="10.1126/science.abb0738">42</jats:related-article> </jats:p>

<jats:p>A famous story about the Beatles tells of the collaboration between Paul McCartney and John Lennon on the song “Getting Better” for their legendary Sgt. Pepper's Lonely Hearts Club Band album. After McCartney wrote the lines “I've got to admit, it's getting better; a little better all the time,” Lennon wryly added, “It can't get no worse.” This story could serve as an epigraph as the calendar turns from the year 2020, which could hardly have gotten much worse, to 2021, when we hope life will indeed get a little better all the time. Better from COVID-19 because of the vaccines, better from misinformation spread by outgoing president Donald Trump and his allies, and better, we can hope, when it comes to the production and distribution of scientific knowledge.</jats:p>

<jats:p>A roundup of weekly science policy and related news</jats:p>

<jats:p>Scientists are scrambling to better understand effects of a series of worrisome mutations</jats:p>

<jats:p>Polymer in mRNA's “packaging” may cause rare anaphylactic reactions</jats:p>

<jats:p>Edwine Barasa helps guide the government's response with data—and quiet persistence</jats:p>

<jats:p>Mapping plan for Arctic refuge ignores risks, critics say</jats:p>

<jats:p>Decreased ocean crust production tied to rapid cooling</jats:p>