X-ray crystallography articles within Nature Chemistry

Featured

  • Research Briefing |

    An infrared laser-induced temperature jump provides a rapid and broadly applicable perturbation to protein dynamics. Temperature-jump crystallography was paired with time-resolved X-ray crystallography to study the dynamic enzyme lysozyme. Measurements with and without a functional inhibitor revealed different patterns in the propagation of motion throughout the enzyme.

  • Article
    | Open Access

    Shifts in temperature alter the structure and dynamics of macromolecules. Now, infra-red laser-induced temperature jump is combined with X-ray crystallography to observe protein structural dynamics in real time. Using this method, motions related to the catalytic cycle of lysozyme, a model enzyme, are visualized at atomic resolution and across broad timescales.

    • Alexander M. Wolff
    • , Eriko Nango
    •  & Michael C. Thompson
  • Article
    | Open Access

    Pump–probe measurements conventionally achieve femtosecond time resolution for X-ray crystallography of reactive processes, but the measured structural dynamics are complex. Using coherent control techniques, we show that the ultrafast crystallographic differences of a fluorescent protein are dominated by ground-state vibrational processes that are unconnected to the photoisomerization reaction of the chromophore.

    • Christopher D. M. Hutchison
    • , James M. Baxter
    •  & Jasper J. van Thor
  • News & Views |

    Tandem cycloaddition reactions have significant applications in organic synthetic chemistry. Now, two enzymes are shown to catalyse tandem hetero-Diels–Alder reactions with a synergistic interplay between a calcium cofactor and N-glycan post-translational modifications during the biosynthesis of bistropolone-sesquiterpene secondary metabolites.

    • Richiro Ushimaru
    •  & Ikuro Abe
  • Article |

    Most chemoproteomic screening approaches are indirect. Now, a chemoproteomic platform based on chiral sulfonyl fluoride probes has been developed for the direct identification of probe-modified tyrosines and lysines in live cells. Stereoselective modification by structurally diverse probes was observed for 634 tyrosines and lysines across functionally diverse protein sites.

    • Ying Chen
    • , Gregory B. Craven
    •  & Jack Taunton
  • Article
    | Open Access

    The metal-dependent, bifunctional isoprenyl diphosphate synthase PcIDS1 from the leaf beetle Phaedon cochleariae integrates substrate, product and metal-ion concentrations to tune its dynamic reactivity. Now structural and functional analyses reveal that this enzyme uses both catalytic centres to form geranyl pyrophosphate, while one domain is inactivated during farnesyl pyrophosphate production.

    • Felix Ecker
    • , Abith Vattekkatte
    •  & Michael Groll
  • Article
    | Open Access

    Ribosomal incorporation of non-α-amino acid monomers into proteins is largely restricted to in vitro translation. Now, pyrrolysyl-transfer RNA synthetase variants have been shown to acylate tRNAs with α-thio acids, malonic acids, and N-formyl amino acids. This work represents a key step towards the programmed ribosomal synthesis of sequence-defined non-protein polymers in cellulo.

    • Riley Fricke
    • , Cameron V. Swenson
    •  & Alanna Schepartz
  • Article
    | Open Access

    In vitro screening of a ribosomally synthesized macrocyclic peptide library containing cyclic γ2,4-amino acids (cγAA) afforded the discovery of potent inhibitors of the SARS-CoV-2 main protease (Mpro). A co-crystal structure revealed the contribution of this cγAA to Mpro binding and the proteolytic stability of these macrocycles.

    • Takashi Miura
    • , Tika R. Malla
    •  & Hiroaki Suga
  • Article
    | Open Access

    The alkaloids crocagins are derived from a ribosomal peptide through a series of enzymatic post-translational modifications. A combination of biochemistry and structural biology techniques has now been used to elucidate this biosynthetic pathway, propose a mechanism for the formation of the tetracyclic core structure and enable genome mining for related natural products.

    • Sebastian Adam
    • , Dazhong Zheng
    •  & Jesko Koehnke
  • News & Views |

    2+2-cycloaddition reactions have long been considered key transformations in the biosynthesis of cyclobutane-containing natural products, but enzymes for these reactions have not yet been identified. Now, a 2+2 cyclase has been discovered, characterized and bioengineered to catalyse cycloadditions with different selectivity.

    • Bo Zhang
    •  & Hui Ming Ge
  • Article |

    A Diels–Alderase that catalyses the inherently disfavoured cycloaddition and forms a bicyclo[2.2.2]diazaoctane scaffold with a strict α-anti-selectivity has now been discovered. This Diels–Alderase, called CtdP, is an NmrA-like protein. Isotopic labelling, structural biology and computational studies reveal that the CtdP-catalysed Diels–Alder reaction involves a NADP+/NADPH-dependent redox mechanism.

    • Zhiwen Liu
    • , Sebastian Rivera
    •  & Xue Gao
  • Article |

    Synthesis of peptidyl-tRNAs is challenging because there are no enzymes that can directly attach the desired peptide to tRNA. Now it has been shown that a chemoenzymatic approach based on native chemical ligation can be used for the semi-synthesis of peptidyl-tRNAs for structural/biochemical studies of arrested and non-arrested ribosome complexes.

    • Egor A. Syroegin
    • , Elena V. Aleksandrova
    •  & Yury S. Polikanov
  • Article |

    The β1-adrenergic receptor (β1AR) contains empty cavities in its preactive conformation, which disappear in the active one. Now, using X-ray crystallography of xenon-derivatized β1AR crystals, a cavity has been shown to be in contact with the cholesterol-binding pocket. Monitoring the binding of a cholesterol analogue in solution has explained the function of cholesterol as a negative allosteric modulator of β1AR.

    • Layara Akemi Abiko
    • , Raphael Dias Teixeira
    •  & Stephan Grzesiek
  • Article |

    A genetically encoded phototrigger based on a xanthone amino acid can expand the scope of time-resolved serial femtosecond crystallography beyond naturally photoactive proteins. This approach has been used to uncover metastable reaction intermediates that occur prior to C–H bond activation in a human liver fatty-acid-binding protein mutant.

    • Xiaohong Liu
    • , Pengcheng Liu
    •  & Jiangyun Wang
  • Article |

    A reduction reaction is usually equated with an electron transfer reaction. Now, ultrafast time-resolved serial femtosecond X-ray crystallography has enabled the visualization of the stepwise structural changes that occur after electron transfers have been observed in the light-triggered reduction of flavin adenine dinucleotide catalysed by DNA photolyase.

    • Manuel Maestre-Reyna
    • , Cheng-Han Yang
    •  & Ming-Daw Tsai
  • Article |

    A chemoenzymatic method to site-specifically conjugate peptide and protein thioesters to folded proteins at lysine residues has been developed. The method uses a genetically encoded four-residue tag that is recognized by the E2 SUMO-conjugating enzyme Ubc9. This approach enables isopeptide formation with just Ubc9 in a programmable manner and obviates the need for E1 and E3 enzymes.

    • Raphael Hofmann
    • , Gaku Akimoto
    •  & Jeffrey W. Bode
  • Article |

    Cyclic β-amino acids can add useful properties to peptides, such as inducing turn structures or providing resistance to proteases. To harness these properties up to ten consecutive cyclic β-amino acids have now been ribosomally incorporated via genetic code reprogramming into a foldamer peptide library that has been screened for potent binders against a protein target, human factor XIIa.

    • Takayuki Katoh
    • , Toru Sengoku
    •  & Hiroaki Suga
  • Article |

    Class II terpene cyclases convert simple linear substrates into complex polycyclic compounds, which typically requires multiple protein domains. Now, a single-domain class II cyclase, a cyanobacterial merosterolic acid synthase, has been identified and characterized. High-resolution X-ray crystal structures provide detailed insights into how a minimalistic enzyme accomplishes this complex cyclization process.

    • Philipp Moosmann
    • , Felix Ecker
    •  & Jörn Piel
  • Article |

    The invariable core of a type II polyketide synthase has been characterized using X-ray crystallography, simulations, mutagenesis experiments and functional assays. The characterization of the ternary acyl carrier protein complexes provides a mechanistic understanding of the reactivity and could inform future engineering of this complex biosynthetic machinery.

    • Alois Bräuer
    • , Qiuqin Zhou
    •  & Michael Groll
  • Article |

    The antibiotic enacyloxin IIa is assembled by a modular polyketide synthase, and released from it by condensation of the enacyloxin acyl chain with 3,4-dihydroxycyclohexane carboxylic acid. A multipronged approach shows the structural basis for recognition between the peptidyl carrier protein domain that bears the acyl chain and the non-ribosomal peptide synthetase condensation domain that ligates it with the carboxylic acid.

    • Simone Kosol
    • , Angelo Gallo
    •  & Józef R. Lewandowski
  • Article |

    The complete biosynthesis of the fungal indole alkaloid malbrancheamide, which culminates in an intramolecular [4+2] hetero-Diels–Alder cyclization to produce the bicyclo[2.2.2]diazaoctane scaffold, has now been discovered. Chemical synthesis and protein structural analysis were used to provide mechanistic insight into this enzyme-dependent diastereo- and enantioselective cycloaddition.

    • Qingyun Dan
    • , Sean A. Newmister
    •  & Robert M. Williams
  • Article |

    The UbiD family of reversible decarboxylases interconvert propenoic or aromatic acids with the corresponding alkenes or aromatic compounds, using a transient 1,3-dipolar cycloaddition between the substrate and the prenylated flavin mononucleotide cofactor. Atomic-resolution crystallography shows targeted destabilization of the intermediate covalent adducts, allowing the enzyme to harness 1,3-dipolar cycloaddition as a readily reversible reaction.

    • Samuel S. Bailey
    • , Karl A. P. Payne
    •  & David Leys
  • Article |

    LepI is an S-adenosylmethionine-dependent pericyclase that catalyses the dehydration, hetero-Diels–Alder reaction and retro-Claisen rearrangement reactions that occur in the formation of the 2-pyridone natural product leporin C. Now, the mechanistic details that underpin this range of catalytic reactions have been uncovered from the crystal structures of LepI and LepI in complex with ligands.

    • Yujuan Cai
    • , Yang Hai
    •  & Yi Tang
  • Article |

    Inhibiting the interaction between amyloid-β (Aβ) and a neuronal cell surface receptor, LilrB2, could offer a potential route for treating Alzheimer’s disease. Now, binding sites between Aβ and LilrB2 have been discovered and computational selection has identified inhibitors that block this binding site. Cell-penetrating inhibitors were found to block the Aβ–LilrB2 interaction and limit Aβ-induced cytotoxicity.

    • Qin Cao
    • , Woo Shik Shin
    •  & Lin Jiang
  • Article |

    Tau aggregation is associated with Alzheimer's disease and dozens of related dementias. Now atomic structures of the aggregation-prone segment VQIINK in repeat 2 of tau have been reported. Inhibitors designed using these structures block seeding by full-length tau better than inhibitors that target the VQIVYK aggregation segment in repeat 3.

    • P. M. Seidler
    • , D. R. Boyer
    •  & D. S. Eisenberg
  • Article |

    Providing detailed structural descriptions of the ultrafast photochemical events that occur in light-sensitive proteins is key to their understanding. Now, excited-state structures in the reversibly switchable fluorescent protein rsEGFP2 have been solved by time-resolved crystallography using an X-ray laser. These structures enabled the design of a mutant with improved photoswitching quantum yields.

    • Nicolas Coquelle
    • , Michel Sliwa
    •  & Martin Weik
  • Review Article |

    Recent years have witnessed a surge of interest in targeted covalent inhibition of disease-associated proteins. Among the electrophiles used to interact with nucleophilic residues in protein structures, boron is unique for its chameleonic ability to display a range of coordination modes upon interaction with protein targets.

    • Diego B. Diaz
    •  & Andrei K. Yudin
  • Article |

    Several natural and unnatural lissoclimide cytotoxins have been prepared via semi-synthesis and total synthesis. An X-ray co-crystal structure of chlorolissoclimide with the ribosome and evaluation of cytotoxicity and translation inhibition of new compounds in the series improves our understanding of the molecular basis for cytotoxicity.

    • Zef A. Könst
    • , Anne R. Szklarski
    •  & Christopher D. Vanderwal
  • Article |

    Berkelium is the only transplutonium element predicted to be able to exhibit both +III and +IV oxidation states in solution. Bk(IV) has now been stabilized through chelation with a siderophore derivative. The resulting neutral coordination compound was characterized and compared with the negatively charged species obtained by chelation of neighbouring trivalent actinides.

    • Gauthier J.-P. Deblonde
    • , Manuel Sturzbecher-Hoehne
    •  & Rebecca J. Abergel
  • Article |

    Time-resolved X-ray crystallography on photoactive yellow protein shows the existence of a short-lived, highly distorted intermediate whose reaction trajectory bifurcates along ‘bicycle-pedal’ and ‘hula-twist’ pathways. The bifurcating reaction pathways can be controlled by weakening the hydrogen bond between the chromophore and an adjacent residue, which switches off the bicycle-pedal pathway.

    • Yang Ouk Jung
    • , Jae Hyuk Lee
    •  & Hyotcherl Ihee
  • Article |

    The interactions of metal ions with metaloxo species are crucial in many important biological processes, such as the oxygen-evolving complex (OEC) in photosystem II, but their exact function remains elusive. Now, the binding of metal ions to a non-haem oxoiron complex has been studied and the observed changes to its electron-transfer properties provide insights into the active site of the OEC.

    • Shunichi Fukuzumi
    • , Yuma Morimoto
    •  & Wonwoo Nam
  • Research Highlights |

    Exposing supramolecular filaments to X-rays results in spontaneous and reversible crystalline ordering.

    • Neil Withers