Volume 8 Issue 7, July 2012

Volume 8 Issue 7

Plants use a hydrophobic cuticle made of cutin and waxes to protect themselves from the environment. Investigation of a tomato mutant deficient in cutin biosynthesis now reveals the first cutin synthase, capable of converting monomeric hydroxyacyl chains into polyesters. This image shows the cuticle (red) and polysaccharide cell wall (blue) of an M82 tomato cultivar. Cover art by Erin Dewalt, based on an image from Gregory Buda. Brief Communication, p609; News & Views, p603

Commentary

  • Commentary |

    Intrinsically disordered proteins and complex multidomain proteins are characterized by a dynamic ensemble of conformations that cannot be unequivocally described by traditional static terms of structural biology. The functional importance of this structural complexity necessitates new standards and protocols for the description and deposition of such 'supertertiary' structural ensembles into structural databases.

    • Peter Tompa

Research Highlights

News and Views

  • News & Views |

    The aerial surfaces of land plants are surrounded by cutin, a strong, lipid-based polymer assembled from glycerol and oxidized fatty acids. The first extracellular enzyme forming polyester linkages that are central to the assembly of cutin is now identified.

    • Fred Beisson
    •  & John Ohlrogge
  • News & Views |

    Modular polyketide synthases are intensively studied as exquisite synthetic machines generating bioactive natural products. The enoylreductase, a common component of these machines, has been structurally and functionally characterized, revealing a new complex architecture.

    • Kenji Arakawa
  • News & Views |

    The proapoptotic cysteine protease caspase-6 participates in the neuropathology of several diseases. Unlike the active dimeric form, the caspase-6 zymogen forms a unique tetramer that can be stabilized by allosteric inhibitors, which prevents caspase-6 activation.

    • Shawn B Bratton
  • News & Views |

    The origin of the flavonoid biosynthetic enzyme chalcone isomerase has remained a mystery. A combination of phylogenetic analysis, crystallography, biochemistry and genetics has uncovered how a stereospecific chalcone isomerase could have evolved from a nonenzymatic ancestral gene.

    • Wendy Ann Peer

Brief Communications

  • Brief Communication |

    Mapping of a mutation in a tomato deficient in the plant cuticle component cutin yields the first cutin synthase, as shown via accumulation of polymer precursors and in vitro oligomerization of synthetic substrates.

    • Trevor H Yeats
    • , Laetitia B B Martin
    • , Hélène M-F Viart
    • , Tal Isaacson
    • , Yonghua He
    • , Lingxia Zhao
    • , Antonio J Matas
    • , Gregory J Buda
    • , David S Domozych
    • , Mads H Clausen
    •  & Jocelyn K C Rose
  • Brief Communication |

    Many efforts to expand the genetic alphabet and reprogram the genetic code have relied on synthetic DNA nucleotides designed to have pairing properties orthogonal to those of natural base pairs. A structural study shows that DNA polymerases enhance the efficiency of non-natural base pair replication by enforcing a standard Watson-Crick geometry in the polymerase active site.

    • Karin Betz
    • , Denis A Malyshev
    • , Thomas Lavergne
    • , Wolfram Welte
    • , Kay Diederichs
    • , Tammy J Dwyer
    • , Phillip Ordoukhanian
    • , Floyd E Romesberg
    •  & Andreas Marx

Articles

  • Article |

    The first crystal structure and in vitro biochemical characterization of an enoylreductase domain from a multimodular polyketide synthase indicates substantial architectural deviations from the mammalian fatty acid synthase and identifies an active site residue that controls catalytic activity.

    • Jianting Zheng
    • , Darren C Gay
    • , Borries Demeler
    • , Mark A White
    •  & Adrian T Keatinge-Clay
  • Article |

    BRET probes that monitor activation of multiple G protein isoforms reveal that angiotensin II and a biased agonist of the angiotensin II type 1A receptor stabilize distinct receptor conformations associated with different signaling outputs.

    • Aude Saulière
    • , Morgane Bellot
    • , Hervé Paris
    • , Colette Denis
    • , Frédéric Finana
    • , Jonas T Hansen
    • , Marie-Françoise Altié
    • , Marie-Hélène Seguelas
    • , Atul Pathak
    • , Jakob L Hansen
    • , Jean-Michel Sénard
    •  & Céline Galés
  • Article |

    The first small-molecule inhibitor of chemoattractant GPCR OXE-R disrupts signaling downstream of Gβγ but not Gαi/o, providing evidence that signaling bias can occur between Gβγ and Gα subunits within a heterotrimer.

    • Stefanie Blättermann
    • , Lucas Peters
    • , Philipp Aaron Ottersbach
    • , Andreas Bock
    • , Viktoria Konya
    • , C David Weaver
    • , Angel Gonzalez
    • , Ralf Schröder
    • , Rahul Tyagi
    • , Petra Luschnig
    • , Jürgen Gäb
    • , Stephanie Hennen
    • , Trond Ulven
    • , Leonardo Pardo
    • , Klaus Mohr
    • , Michael Gütschow
    • , Akos Heinemann
    •  & Evi Kostenis
  • Article |

    A computational screen identifies a small-molecule activator of proapoptotic BAX that selectively binds to the BAX trigger site, inducing characteristic conformational changes, oligomerization and BAX-dependent cell death.

    • Evripidis Gavathiotis
    • , Denis E Reyna
    • , Joseph A Bellairs
    • , Elizaveta S Leshchiner
    •  & Loren D Walensky
  • Article |

    A genetic synthetic lethal screen reveals that ATM and MET kinases promote cell survival upon activation of p53 with Nutlin-3, and these survival pathways act in parallel to canonical cell cycle arrest and apoptotic genes induced by p53.

    • Kelly D Sullivan
    • , Nuria Padilla-Just
    • , Ryan E Henry
    • , Christopher C Porter
    • , Jihye Kim
    • , John J Tentler
    • , S Gail Eckhardt
    • , Aik Choon Tan
    • , James DeGregori
    •  & Joaquín M Espinosa
  • Article |

    Phage display reveals peptides that bind to the caspase-6 zymogen, inducing its tetramerization and specifically inhibiting its enzyme activity both in vitro and in neuronal cells.

    • Karen Stanger
    • , Micah Steffek
    • , Lijuan Zhou
    • , Christine D Pozniak
    • , Clifford Quan
    • , Yvonne Franke
    • , Jeff Tom
    • , Christine Tam
    • , Irina Krylova
    • , J Michael Elliott
    • , Joseph W Lewcock
    • , Yingnan Zhang
    • , Jeremy Murray
    •  & Rami N Hannoush
  • Article |

    Fluorinated, cell-permeable analogs of sialic acid and fucose are processed by monosaccharide salvage pathways to generate sialyl- and fucosyltransferase inhibitors intracellularly. These compounds serve as important new tools to dissect the role of glycan modifications within complex biological systems.

    • Cory D Rillahan
    • , Aristotelis Antonopoulos
    • , Craig T Lefort
    • , Roberto Sonon
    • , Parastoo Azadi
    • , Klaus Ley
    • , Anne Dell
    • , Stuart M Haslam
    •  & James C Paulson