Biochemistry

  • Article
    | Open Access

    The tumor suppressor p53 is mutated in more than half of human cancers and the compound methylene quinuclidinone (MQ) was shown to reactivate p53 mutants by binding covalently to cysteine residues. Here, the authors present crystal structures of wild-type and cancer related p53 mutant core domains bound to MQ alone and in complex with their DNA response elements and observe that MQ is bound to several cysteine residues located at the surface of the core domain.

    • Oksana Degtjarik
    • , Dmitrij Golovenko
    •  & Zippora Shakked
  • Article
    | Open Access

    The authors present DeepRank, a deep learning framework for the data mining of large sets of 3D protein-protein interfaces (PPI). They use DeepRank to address two challenges in structural biology: distinguishing biological versus crystallographic PPIs in crystal structures, and secondly the ranking of docking models.

    • Nicolas Renaud
    • , Cunliang Geng
    •  & Li C. Xue
  • Article
    | Open Access

    Steviol glycosides from the plant Stevia rebaudiana are already used as lowcalorie sweeteners, but the most abundant naturally occurring compounds have a bitter aftertaste. Here, the authors characterize and engineer rice glycosyltransferase OsUGT91C1 to facilitate the large-scale production of naturally rare but palatable glycosides Reb D and Reb M

    • Jinzhu Zhang
    • , Minghai Tang
    •  & Wei Cheng
  • Article
    | Open Access

    Eph receptor tyrosine kinases and their ephrin ligands mediate cell-cell communication. Here, the authors assess the structure and dynamics of the EphA2 intracellular region and uncover complex effects of phosphorylation within the linker region between EphA2 kinase and SAM domains.

    • Bernhard C. Lechtenberg
    • , Marina P. Gehring
    •  & Elena B. Pasquale
  • Article
    | Open Access

    The spatial organization of cell surface receptors is critical for cell signaling and drug action. Here, the authors develop an optoproteomic method for mapping surface protein interactions, revealing cellular responses to antibodies, drugs and viral particles as well as immunosynapse signaling events.

    • Maik Müller
    • , Fabienne Gräbnitz
    •  & Bernd Wollscheid
  • Article
    | Open Access

    UvrD is a model helicase from the non-hexameric Superfamily 1. Here, the authors use optical tweezers to measure directly the stepwise translocation of UvrD along a DNA hairpin, and propose a mechanism in which UvrD moves one base pair at a time, but sequesters the nascent single strands, releasing them after a variable number of ATP hydrolysis cycles.

    • Sean P. Carney
    • , Wen Ma
    •  & Yann R. Chemla
  • Article
    | Open Access

    Rearrangement hot spots (Rhs) proteins are bacterial polymorphic toxin systems. Here, the authors show that Rhs1 forms a complex with the Type VI secretion system (T6SS) spike protein VgrG and the EagR chaperone. They also present the cryo-EM structure of the Rhs1-EagR complex and propose a model for Rhs loading and delivery by the T6SS.

    • Dukas Jurėnas
    • , Leonardo Talachia Rosa
    •  & Eric Cascales
  • Article
    | Open Access

    Nucleosomes form arrays with even spacing between them in virtually all eukaryotes; however, their biogenesis is incompletely understood. Here the authors show that nucleosome density and DNA sequence along with the Ino80 chromatin remodeling complex play a role in nucleosome array formation in yeast and that the transcriptional machinery disrupts evenly-spaced nucleosomes.

    • Ashish Kumar Singh
    • , Tamás Schauer
    •  & Felix Mueller-Planitz
  • Article
    | Open Access

    CDP-diacylglycerol (CDP-DAG) alcohol O-phosphatidyl transferases (CDP-APs) are conserved in archaea, bacteria, and eukaryotes and catalyze the de novo synthesis of phospho-lipids from the precursor CDP-DAG and an alcohol. Here, the authors present the crystal structures of the Methanocaldococcus jannaschii phosphatidyl serine synthase (MjPSS) in four different states and suggest a model for its catalytic mechanism.

    • Martin Centola
    • , Katharina van Pee
    •  & Özkan Yildiz
  • Article
    | Open Access

    Ty3 retrotransposon integrates with an exquisite specificity upstream of RNA Polymerase III-transcribed genes, such as transfer RNAs. Here the authors resolve a cryo-EM structure of an active Ty3 intasome in complex with a TFIIIB-bound tRNA promoter, shedding light into the molecular determinants of harmless retrotransposition.

    • Guillermo Abascal-Palacios
    • , Laura Jochem
    •  & Alessandro Vannini
  • Article
    | Open Access

    Here, the authors combine single-molecule atomic force spectroscopy measurements and molecular dynamics simulations to investigate the binding of spike proteins from four SARS-CoV-2 variants of concern (VoC) to the human ACE2 receptor. They observe an increase in the RBD-ACE2 complex stability for several of the VoCs and derive how the mutations affect the kinetic, thermodynamic and structural properties of complex formation.

    • Melanie Koehler
    • , Ankita Ray
    •  & David Alsteens
  • Article
    | Open Access

    The venom of Latrodectus spiders contains seven Latrotoxins (LaTXs), among them α-latrocrustatoxin (LCT) and δ- latroinsectotoxins δ-LIT. LaTXs bind to specific receptors on the surface of neuronal cells and target the molecular exocytosis machinery. Here, the authors present the cryo-EM structure of the α-LCT monomer and the δ-LIT dimer, which reveal that LaTXs are organized in four domains and they discuss the potential oligomerisation mechanism that takes place before LaTXs membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca2+ ions.

    • Minghao Chen
    • , Daniel Blum
    •  & Christos Gatsogiannis
  • Article
    | Open Access

    Entry into S phase of the cell cycle is regulated positively by mitogens and negatively by DNA damage; however, how balance of these signals is achieved is not well known. Here the authors show that the NUCKS1-SKP2- p21/p27 axis integrates this information, where the NUCKS1 transcription factor affects levels of p21/p27 to readout the mitogen:DNA damage balance and regulate S phase entry decision.

    • Samuel Hume
    • , Claudia P. Grou
    •  & Grigory L. Dianov
  • Article
    | Open Access

    Dispatched (Disp) RND transporter, activated by Furin-mediated proteolytic cleavage, mediates the release of the lipid-modified Hedgehog (Hh) ligands. Here, the authors report structures of human Disp1 (hDisp1) before and after cleavage, and in complex with lipid-modified Sonic hedgehog (Shh), with insights into the mechanisms of hDisp1 activation and function.

    • Wanqiu Li
    • , Linlin Wang
    •  & Xin Gong
  • Article
    | Open Access

    Starch is the major form of energy storage in plant cells and forms discrete, semi-crystalline granules within plastids. Here the authors use electron tomography and nanoSIMS to show that Arabidopsis starch granules initiate in stromal pockets between thylakoid membranes that coalesce before growing anisotropically.

    • Léo Bürgy
    • , Simona Eicke
    •  & Samuel C. Zeeman
  • Article
    | Open Access

    Protein turnover underpins biology but is challenging to measure in vivo across the entire proteome. Here, the authors provide a comprehensive resource of protein turnover in mouse tissues and develop a visualization platform to analyze these data.

    • Zach Rolfs
    • , Brian L. Frey
    •  & Nathan V. Welham
  • Article
    | Open Access

    Microbial DNA glycosylases associated with the biosynthesis of DNA-damaging antibiotics have evolved self-resistance for their cognate natural products. Here, the authors provide evidence that cellular self-resistance is enabled by reduced affinity of the glycosylases for the excision products of the corresponding DNA lesions.

    • Elwood A. Mullins
    • , Jonathan Dorival
    •  & Brandt F. Eichman
  • Article
    | Open Access

    AGPATs (1-acylglycerol-3-phosphate O-acyltransferases) catalyze the acylation of lysophosphatidic acid to form phosphatidic acid (PA), a key step in the synthesis of all glycerolipids. Here, the authors show that AGPAT2 and CDP-DAG synthases (CDS1 and CDS2) form functional complexes that promote further conversion of PA along the CDP-DAG pathway of phospholipid synthesis.

    • Hoi Yin Mak
    • , Qian Ouyang
    •  & Hongyuan Yang
  • Article
    | Open Access

    Tweety Homologs (TTYHs) are highly conserved membrane proteins, whose functions remain poorly understood. Here, the authors present the cryo-EM structures of murine TTYH2 and TTYH3 that form cis-dimers in the presence of Ca2+, whereas in the absence of Ca2+ TTYH2 adopts monomeric and trans-dimeric structures. The presented structures lack ion conducting pathways, which is consistent with results from electrophysiology measurements.

    • Baobin Li
    • , Christopher M. Hoel
    •  & Stephen G. Brohawn
  • Article
    | Open Access

    Simultaneous targeting of BCL-xL and BCL-2 is an attractive approach for cancer treatment. Based on information gained by computational structure modelling, the authors develop a PROTAC that induces degradation of both BCL-xL and BCL-2 and effectively targets BCL-xL/2-dependent leukaemia cells.

    • Dongwen Lv
    • , Pratik Pal
    •  & Daohong Zhou
  • Article
    | Open Access

    RNA of some viruses is protected from degradation by a 5′ triphosphate group. Here the authors identify nudix hydrolase 2 (NUDT2) as novel antiviral defense protein that dephosphorylates viral RNA and thereby enables its degradation.

    • Beatrice T. Laudenbach
    • , Karsten Krey
    •  & Andreas Pichlmair
  • Article
    | Open Access

    During phosphatidylcholine (PC) remodeling re-acylation is catalyzed by lysophosphatidylcholine acyltransferases (LPCAT). Here, the authors present crystal and cryo-EM structures of chicken LPCAT3 in the apo-, acyl donor-bound and acyl receptor-bound states, and based on the structures and further functional analysis they discuss the mechanism of the enzyme.

    • Qing Zhang
    • , Deqiang Yao
    •  & Yu Cao
  • Article
    | Open Access

    DNA transfer between two bacterial cells is mediated by the conjugative type 4 secretion systems (T4SSs). Here, the authors report the structure of a complete T4SS outer-membrane core complex (OMCC), revealing distinct C17 and C13 symmetries of its central inner and peripheral outer ring regions, respectively.

    • Himani Amin
    • , Aravindan Ilangovan
    •  & Tiago R. D. Costa
  • Article
    | Open Access

    Vpr is a HIV-1 accessory virulence factor that also interacts with the human DNA repair protein hHR23A. Here, the authors present the structure of Vpr in complex with the C-terminal half of hHR23A comprising the XPC-binding and ubiquitin-associated domains, which reveals that hHR23A interacts with the DCAF1-binding and not the substrate-binding Vpr surface and further illustrates how Vpr acts as a versatile structural adapter that targets diverse DNA repair pathways.

    • In-Ja L. Byeon
    • , Guillermo Calero
    •  & Angela M. Gronenborn
  • Article
    | Open Access

    Resistance-nodulation-cell division (RND)-type tripartite efflux pumps confer multidrug resistance to Gram-negative bacteria. Here, structural and functional analyses of AdeB from Acinetobacter baumannii and AcrB from Escherichia coli provide insight into their different drug-binding and conformational drug transport states.

    • Alina Ornik-Cha
    • , Julia Wilhelm
    •  & Klaas M. Pos
  • Article
    | Open Access

    Rational design of enzymes with new or improved properties is rarely straightforward, and artificial selection pressure approaches that link an improvement in the target to cell growth are an alternative. Here, the authors show that diverse enzymes sharing the ubiquitous cofactor NAD(P)+ can substitute for defective NAD+ regeneration, representing a very broadly-applicable artificial selection.

    • Lara Sellés Vidal
    • , James W. Murray
    •  & John T. Heap
  • Article
    | Open Access

    The orphan GPR158 receptor belongs to the class C GPCR family and interacts with the regulator of G protein signaling 7 (RGS7)-Gβ5 complex. Here, the authors present the cryo-EM structure of human GPR158, which reveals that the extracellular domain contains a PAS domain, and they also determine the structures of GPR158 in complex with either one or two RGS7-Gβ5 heterodimers and discuss implications for the signaling mechanism.

    • Eunyoung Jeong
    • , Yoojoong Kim
    •  & Yunje Cho
  • Article
    | Open Access

    UBE3A gene dysregulation is associated with neurodevelopmental disorders, but predicting the function of UBE3A variants remains difficult. The authors use a high-throughput assay to categorize variants by functional activity, and show that UBE3A hyperactivity increases the risk of neurodevelopmental disease.

    • Kellan P. Weston
    • , Xiaoyi Gao
    •  & Jason J. Yi
  • Article
    | Open Access

    Endogenous ACE2 is a receptor for SARS-CoV-2 and a recombinant soluble ACE2 protein can inhibit SARS-CoV-2 infection acting as a decoy. Here the authors show that B38-CAP, an ACE2-like enzyme but not a decoy for the virus, is protective against SARS-CoV-2-induced lung injury in animal models.

    • Tomokazu Yamaguchi
    • , Midori Hoshizaki
    •  & Keiji Kuba
  • Article
    | Open Access

    The pseudokinase MLKL is activated by the upstream kinase RIPK3 in the necroptotic pathway but the structural basis of MLKL activation is not well understood yet. Here, the authors present the crystal structures of the human RIPK3:MLKL complex and human RIPK3 kinase alone, which reveal structural differences between human and murine RIPK3 and they discuss mechanistic implications.

    • Yanxiang Meng
    • , Katherine A. Davies
    •  & James M. Murphy
  • Article
    | Open Access

    Many interactions between viral and host proteins are mediated by short peptide motifs. Here, using a phage-based viral peptide library, the authors identify 269 peptide-based interactions for 18 coronaviruses, including an interaction between SARS-CoV-2 N and G3BP1/2 that affects stress granules.

    • Thomas Kruse
    • , Caroline Benz
    •  & Ylva Ivarsson
  • Article
    | Open Access

    L-asparaginases catalyse the hydrolysis of L-asparagine to L-aspartic acid and ammonia. Here, the authors present high resolution crystal structures of Rhizobium etli L-asparaginase that contains a Zn2+ binding site without a catalytic role and discuss the catalytic mechanism of the enzyme.

    • Joanna I. Loch
    • , Barbara Imiolczyk
    •  & Mariusz Jaskolski
  • Article
    | Open Access

    The impact of genetic fusions on degrons, which are motifs for ubiquitin-mediated protein degradation, has not been fully explored. Here, the authors analyse fusion genes affecting degrons in pan-cancer genomics data, validate their functional impact and find enrichment for both internal and C-terminal degron losses.

    • Jing Liu
    • , Collin Tokheim
    •  & Wenyi Wei
  • Article
    | Open Access

    The V3-crown of the HIV-1 envelope protein largely elicits non-neutralizing antibodies. Here, the authors show that the V3-crown can be targeted by broadly neutralizing designed ankyrin repeat proteins recognizing two conformations one of which resembles CCR5- bound V3.

    • Nikolas Friedrich
    • , Emanuel Stiegeler
    •  & Alexandra Trkola
  • Article
    | Open Access

    Targeting tumor-associated antigens in paediatric medulloblastomas (MB) is challenging due to their low mutational burden. Here, the authors develop a sensitive proteogenomic approach to identify tumour specific neoantigens, which may enable personalised T cell immunotherapy in paediatric MB.

    • Samuel Rivero-Hinojosa
    • , Melanie Grant
    •  & Brian R. Rood
  • Article
    | Open Access

    The coverage and throughput of data-independent acquisition (DIA)-based phosphoproteomics is limited by its dependence on experimental spectral libraries. Here the authors develop a DIA workflow based on in silico spectral libraries generated by a novel deep neural network to expand phosphoproteome coverage.

    • Ronghui Lou
    • , Weizhen Liu
    •  & Wenqing Shui