Catálogo de publicaciones - revistas

<jats:title>A GPCR seen in the active state</jats:title> <jats:p> G protein–coupled receptors (GPCRs) are exceptionally good targets for drug development. Warne <jats:italic>et al.</jats:italic> describe four crystal structures of complexes of a GPCR—the β1-adrenergic receptor—in its active state. They used nanobodies (recombinant variable domains of heavy-chain antibodies) and engineered G protein to stabilize the β1-adrenergic receptor bound to a full agonist, two partial agonists, and a weak partial agonist. Comparison of these structures to the inactive state elucidates how agonist binding is altered in the active conformation. </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="6442" page="775" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aau5595">775</jats:related-article> </jats:p>

<jats:title>A race against time</jats:title> <jats:p> Clinically relevant antimicrobial resistance is largely spread via plasmids that disperse among bacteria during conjugation. How quickly can a resistance gene be expressed after transfer? In susceptible bacterial cells, tetracycline should inhibit protein synthesis, including from the plasmid-transferred resistance gene <jats:italic>tetA</jats:italic> . Unexpectedly, Nolivos <jats:italic>et al.</jats:italic> found that TetA can be expressed despite the presence of tetracycline (see the Perspective by Povolo and Ackermann). Immediately after plasmid transfer into a cell, TetA synthesis starts because its repressor is slow to be expressed. In addition, the ubiquitous xenobiotic efflux pump AcrAB-TolC buys time for TetA translation by keeping tetracycline concentration below toxic levels. </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="6442" page="778" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aav6390">778</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6442" page="737" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax6620">737</jats:related-article> </jats:p>

<jats:title>A portfolio of habitats</jats:title> <jats:p> To conserve species, we must conserve their habitat. This concept is well known, but the reality is much more complex than simply conserving a particular area. Habitats are dynamic and vary across both space and time. Such variation can help to facilitate long-term persistence of species by allowing local movement in search of the best conditions. Brennan <jats:italic>et al.</jats:italic> clearly demonstrate the benefit of the habitat mosaic to Pacific salmon by characterizing how both climate and population productivity vary over time and space in an Alaskan river system. </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="6442" page="783" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aav4313">783</jats:related-article> </jats:p>

<jats:title>Divergent protein kinase</jats:title> <jats:p> SidJ is a protein produced by <jats:italic>Legionella pneumophila</jats:italic> that orchestrates this intracellular pathogen's establishment within the host cell. SidJ prevents lysosome fusion with the vacuole, within which the bacterium resides and replicates. SidJ also modulates the toxicity of the SidE family ubiquitin ligases that catalyze phosphoribosyl-linked host protein ubiquitination. Black <jats:italic>et al.</jats:italic> discovered that SidJ is activated by host calmodulin. Furthermore, although SidJ has a pseudokinase fold, it does not phosphorylate SidE proteins but polyglutamylates them instead. The in vivo relevance of this mechanism for bacterial infectivity was verified in the natural reservoir host <jats:italic>Acanthamoeba castellanii</jats:italic> . </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="6442" page="787" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw7446">787</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>