Volume 8 Issue 2, February 2016

Volume 8 Issue 2

The mechanism by which RNA and proteins form liquid organelles is not fully understood, but William Aumiller Jr and Christine Keating have now demonstrated that charge-mediated phase separation can generate droplets that resemble a simple model of these assemblies. By controlling the phosphorylation of cationic peptides using a kinase/phosphatase enzyme pair, Aumiller and Keating were able to reversibly form and dissolve liquid droplets from the peptides and RNA. The cover image depicts the formation of liquid organelles of different sizes.Article p129IMAGE: CHRISTINE KEATING AND WILLIAM AUMILLER JRCOVER DESIGN: KAREN MOORE

Editorial

Thesis

  • Thesis |

    A day in the life of an academic, as told by Bruce C. Gibb.

    • Bruce C. Gibb

News and Views

  • News & Views |

    Mass production at the nanoscale requires molecular machines that can control, with high fidelity, the spatial orientation of other reactive species. The demonstration of a synthetic system in which a molecular robotic arm can be used to manipulate the position of a chemical cargo is a significant step towards achieving this goal.

    • Ivan Aprahamian
  • News & Views |

    The reactivity of glycosyl donors is often explained by invoking putative glycosyl cation intermediates but, until now, they have not been observed in the condensed phase.

    • Luis Bohé
    •  & David Crich

Perspectives

Articles

  • Article |

    Incorporation of a π-clamp—a four-residue sequence (Phe-Cys-Pro-Phe)—into a protein enables the site-specific modification of the π-clamp cysteine side-chain. The π-clamp can be genetically encoded and does not require protecting-groups or catalysts to provide selective conjugation.

    • Chi Zhang
    • , Matthew Welborn
    • , Tianyu Zhu
    • , Nicole J. Yang
    • , Michael S. Santos
    • , Troy Van Voorhis
    •  & Bradley L. Pentelute
  • Article |

    Intracellular bodies called liquid organelles are rich in nucleic acids and proteins, and are thought to occur by liquid–liquid phase coexistence. Now, enzymatic control over the phosphorylation state of a simple cationic peptide, thereby altering its electrostatic interaction with RNA, has been shown to drive formation and dissolution of droplets that mimic these intracellular liquid bodies.

    • William M. Aumiller Jr
    •  & Christine D. Keating
  • Article |

    Factory assembly lines often feature robots that pick up, reposition and connect components in a programmed manner. Now, it has been shown that a molecular machine is able to pick up a cargo, reposition it, set it down and release it at a site approximately 2 nm away from the starting position.

    • Salma Kassem
    • , Alan T. L. Lee
    • , David A. Leigh
    • , Augustinas Markevicius
    •  & Jordi Solà
  • Article |

    Single operation transformations that enantioselectively install a stereogenic centre while introducing a distal functional group are synthetically valuable but rare processes. Now, a copper-catalysed reductive relay hydroamination process that simultaneously creates a remote chiral centre is described. The resulting γ- and δ-chiral amines are important structural elements in many pharmaceutical agents and natural products.

    • Shaolin Zhu
    • , Nootaree Niljianskul
    •  & Stephen L. Buchwald
  • Article |

    Little is known about how the identity of a leaving group affects the dynamics of a bimolecular nucleophilic substitution reaction. A study of the reaction of F with CH3Cl, and comparison to its reaction with CH3I, now reveals key insights into such effects, with reactant orientation considered a key factor in understanding the behaviour observed.

    • Martin Stei
    • , Eduardo Carrascosa
    • , Martin A. Kainz
    • , Aditya H. Kelkar
    • , Jennifer Meyer
    • , István Szabó
    • , Gábor Czakó
    •  & Roland Wester
  • Article |

    The selective conversion of abundant and inexpensive alkane feedstocks into value-added speciality chemicals is a significant and challenging goal, and methods for catalytically converting alkanes into useful linear alkylsilanes are unknown, to date. Now, a strategy combining alkane dehydrogenation with regioselective olefin isomerization–hydrosilylation to produce linear alkylsilanes is described.

    • Xiangqing Jia
    •  & Zheng Huang
  • Article |

    DNA nanostructures are typically used as molecular scaffolds. Now, it has been shown that they can also act as reusable templates for ‘molecular printing’ of DNA strands onto gold nanoparticles. The products inherit the recognition elements of the parent template: number, orientation and sequence asymmetry of DNA strands. This converts isotropic nanoparticles into complex building blocks.

    • Thomas G. W. Edwardson
    • , Kai Lin Lau
    • , Danny Bousmail
    • , Christopher J. Serpell
    •  & Hanadi F. Sleiman
  • Article |

    Doping mesoporous materials is an attractive way to tune their properties, but typically disrupts the host materials’ structures. Ultrasmall graphitic pencil nanodots have now been prepared, doped with heteroatoms, and inserted in a well-dispersed manner within the ordered structure of mesoporous materials including TiO2, carbon and silica, by a co-assembly approach.

    • Biao Kong
    • , Jing Tang
    • , Yueyu Zhang
    • , Tao Jiang
    • , Xingao Gong
    • , Chengxin Peng
    • , Jing Wei
    • , Jianping Yang
    • , Yongcheng Wang
    • , Xianbiao Wang
    • , Gengfeng Zheng
    • , Cordelia Selomulya
    •  & Dongyuan Zhao
  • Article |

    The encapsulation and stabilization of an oxygen tolerant [NiFe]-hydrogenase, sequestered within the bacteriophage P22 capsid, has now been achieved through a directed self-assembly process. Probing the catalytic activity and infrared spectroscopic signatures of the bio-inspired assembly shows that the capsid provides stability and protection to the hydrogenase cargo.

    • Paul C. Jordan
    • , Dustin P. Patterson
    • , Kendall N. Saboda
    • , Ethan J. Edwards
    • , Heini M. Miettinen
    • , Gautam Basu
    • , Megan C. Thielges
    •  & Trevor Douglas
  • Article |

    Glycosyl cations are universally accepted as key intermediates in the mechanism of glycosylation—the reaction that covalently links carbohydrates to other molecules—but their high reactivity makes them difficult to characterize. Using HF/SbF5 superacid, two glucosyl cations have been generated and stabilized, then characterized by NMR spectroscopy aided by computation and their conformation elucidated.

    • A. Martin
    • , A. Arda
    • , J. Désiré
    • , A. Martin-Mingot
    • , N. Probst
    • , P. Sinaÿ
    • , J. Jiménez-Barbero
    • , S. Thibaudeau
    •  & Y. Blériot

In Your Element

  • In Your Element |

    Peter Dinér describes the journey of yttrium from its discovery in a remote mine to high-temperature superconductors and light-emitting diodes.

    • Peter Dinér