<i>ykkC</i> riboswitches employ an add-on helix to adjust specificity for polyanionic ligands

August 17th, 2018 by Alla Peselis

ykkC riboswitches employ an add-on helix to adjust specificity for polyanionic ligands

<i>ykkC</i> riboswitches employ an add-on helix to adjust specificity for polyanionic ligands, Published online: 17 August 2018; doi:10.1038/s41589-018-0114-4

Structural analysis of PRPP and ppGpp riboswitches reveals that they employ a helical element to create a tunnel for the ligand, whose specificity is determined by the conserved nucleotides forming the tunnel and long-distance contacts.
  • Posted in Nat Chem Biol, Publications
  • Comments Off on <i>ykkC</i> riboswitches employ an add-on helix to adjust specificity for polyanionic ligands

TA gets a PG rating

August 17th, 2018 by Mirella Bucci

TA gets a PG rating

TA gets a PG rating, Published online: 17 August 2018; doi:10.1038/s41589-018-0126-0

TA gets a PG rating

Stuck on you

August 17th, 2018 by Caitlin Deane

Stuck on you

Stuck on you, Published online: 17 August 2018; doi:10.1038/s41589-018-0124-2

Stuck on you

Mimicking cross-α amyloids

August 17th, 2018 by Meytal Landau

Mimicking cross-α amyloids

Mimicking cross-α amyloids, Published online: 17 August 2018; doi:10.1038/s41589-018-0118-0

The design of spiraling cross-α amyloid-like structures reveals fascinating supermolecular fibrils of diverse compactness and stability. The small sequence variations governing cross-α self-assembly properties concur with amyloids being basic building blocks of life and natural targets for microbial structural mimicry.

Allosteric mechanisms underlie GPCR signaling to SH3-domain proteins through arrestin

August 17th, 2018 by Fan Yang

Allosteric mechanisms underlie GPCR signaling to SH3-domain proteins through arrestin

Allosteric mechanisms underlie GPCR signaling to SH3-domain proteins through arrestin, Published online: 17 August 2018; doi:10.1038/s41589-018-0115-3

NMR and in vitro reconstitution indicate that GPCRs signal through SH3-containing proteins downstream of β-arrestin 1 proline regions and that arrestin allosterically activates downstream kinases by disrupting their autoinhibitory conformation.
  • Posted in Nat Chem Biol, Publications
  • Comments Off on Allosteric mechanisms underlie GPCR signaling to SH3-domain proteins through arrestin

An optical sensor to monitor dynamics of extracellular glycine

August 17th, 2018 by Dmitri A. Rusakov

An optical sensor to monitor dynamics of extracellular glycine

An optical sensor to monitor dynamics of extracellular glycine, Published online: 17 August 2018; doi:10.1038/s41589-018-0123-3

A computational design approach was used to develop a genetically encoded FRET-based optical sensor that is aimed at monitoring extracellular glycine levels in brain tissue with the sensitivity and resolution to discern differences in dendritic spine and shaft environment and concentration dynamics upon afferent stimulation.

[ASAP] A New Class of EutT ATP:Co(I)rrinoid Adenosyltransferases Found in <italic toggle=”yes”>Listeria monocytogenes</italic> and Other <italic toggle=”yes”>Firmicutes</italic> Does Not Require a Metal Ion for Activity

August 15th, 2018 by Flavia G. Costa, Jorge C. Escalante-Semerena

TOC Graphic

Biochemistry
DOI: 10.1021/acs.biochem.8b00715

Poxviral protein E3-altered cytokine production reveals that DExD/H-box helicase 9 controls Toll-like receptor-stimulated immune responses [Signal Transduction]

August 15th, 2018 by Alan Dempsey, Sinead E. Keating, Michael Carty, Andrew G. Bowie

Host pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) detect viruses and other pathogens, inducing production of cytokines that cause inflammation and mobilize cells to control infection. Vaccinia virus (VACV) encodes proteins that antagonize these host innate immune responses, and elucidating the mechanisms of action of these viral proteins helped shed light on PRR signalling mechanisms. The VACV virulence factor E3 is one of the most intensely studied VACV proteins and has multiple effects on host cells, many of which cannot be explained by the currently known cellular targets of E3. Here, we report that E3 expression in human monocytes alters TLR2- and TLR8-dependent cytokine induction, and particularly inhibits IL-6. Using MS, we identified DExD/H-box helicase 9 (DHX9) as an E3 target. Although DHX9 has previously been implicated as a PRR for sensing nucleic acid in dendritic cells, we found no role for DHX9 as a nucleic acid-sensing PRR in monocytes. Rather, DHX9 suppression in these cells phenocopied the effects of E3 expression on TLR2- and TLR8-dependent cytokine induction, in that DHX9 was required for all TLR8-dependent cytokines measured, and for TLR2-dependent IL-6. Further, DHX9 also had a cell- and stimulus-independent role in IL-6 promoter induction. DHX9 enhanced nuclear factor kappa B (NFkB)-dependent IL-6 promoter activation, which was directly antagonized by E3. These results indicate new roles for DHX9 in regulating cytokines in innate immunity and reveal that VACV E3 disrupts innate immune responses by targeting of DHX9.
  • Posted in Journal of Biological Chemistry, Publications
  • Comments Off on Poxviral protein E3-altered cytokine production reveals that DExD/H-box helicase 9 controls Toll-like receptor-stimulated immune responses [Signal Transduction]

[ASAP] Human Milk Oligosaccharides (HMOs) Sensitize Group B <italic toggle=”yes”>Streptococcus</italic> to Clindamycin, Erythromycin, Gentamicin, and Minocycline on a Strain Specific Basis

August 5th, 2018 by Kelly M. Craft, Jennifer A. Gaddy, Steven D. Townsend

TOC Graphic

ACS Chemical Biology
DOI: 10.1021/acschembio.8b00661
  • Posted in ACS Chemical Biology, Publications
  • Comments Off on [ASAP] Human Milk Oligosaccharides (HMOs) Sensitize Group B <italic toggle=”yes”>Streptococcus</italic> to Clindamycin, Erythromycin, Gentamicin, and Minocycline on a Strain Specific Basis

[ASAP] Discovery of a Nitric Oxide Responsive Quorum Sensing Circuit in <italic toggle=”yes”>Vibrio cholerae</italic>

August 2nd, 2018 by Sajjad Hossain, Ilana Heckler, Elizabeth M. Boon

TOC Graphic

ACS Chemical Biology
DOI: 10.1021/acschembio.8b00360
  • Posted in ACS Chemical Biology, Publications
  • Comments Off on [ASAP] Discovery of a Nitric Oxide Responsive Quorum Sensing Circuit in <italic toggle=”yes”>Vibrio cholerae</italic>