October 2015 issue
A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs.
The crystal structure of an Rsd–HPr complex was determined in order to reveal the binding interface between Rsd and HPr. A molecular link between global gene regulation and nutrient availability is described.
The crystal structure of glyoxalase I from Z. mays is reported.
Lattice vibrations account for the structured component of the diffuse scatter produced by crystals of the 70S ribosome from T. thermophilus.
Nicotinamide mononucleotide adenylyltransferase (NMNAT) catalyzes the biosynthesis of NAD+ and NaAD+. Surprisingly, when expressed in E. coli, NMNAT mutants trapped a molecule of NADP+ in their active sites. This NADP+ was bound in a conformation that was quite different from that displayed by NAD+ in the native enzyme complex.
A combination of crystal-contact engineering and surface-entropy reduction was used to enable the crystallization and subsequent structural solution of two spliceosomal assembly intermediates.
Structural and functional studies of a metallo-β-lactamase reveal a new type of structurally encoded nickel-containing heterodinuclear site.
In vitro neuromuscular studies were performed to demonstrate that suramin neutralizes the toxic activity of a PLA2-like protein, corroborating calorimetric assays. Crystallographic studies demonstrated that the inhibitor binds to the surface of the toxin, obstructing its membrane docking and disruption sites and confirming the proposed myotoxic mechanism.
A method is reported for collecting room-temperature data from protein crystals under vacuum by protecting them with a thin graphene layer.
Epsilon-class glutathione S-transferases (GSTs) are found in invertebrates, including many insects, where they play roles in the detoxication of insecticides and in development. The crystal structures of two epsilon-class GSTs from D. melanogaster are reported and compared to aid in the characterization of the functional differences between the isozymes.
The crystal structure of the broadly neutralizing antibodies 8ANC195 and PGT128 bound to an HIV-1 envelope trimer has been determined. Structural and binding analyses have elucidated the full epitopes for these antibodies in the context of the intact viral glycoprotein, providing improved templates for HIV-1 vaccine design.
The crystal structures of two constructs of RC1339/APRc from R. conorii, consisting of either residues 105–231 or 110–231 followed by a His tag, have been determined in three different crystal forms. The monomer of APRc assumes a retropepsin-like fold, but the dimer observed in all crystal forms is entirely different from the canonical dimer of retropepsins.
The self-complementary DNA decamer d(GCATGCATGC) crystallizes as an unusual double-folded structure, which serves as the basis for a possible structural model of triplet-repeat DNA sequences.
Structural insight is provided into the mechanism by which a widespread family of bacterial chemotaxis receptors containing the periplasmic tandem Per–Arnt–Sim (PAS) sensing domain recognize free amino acids, and a model for signal transduction across the membrane is proposed.
The high-resolution structure of uracil-DNA N-glycosylase (UNG) from D. radiodurans in complex with DNA provides support for a model in which DNA compression and minor-groove stabilization is crucial for the uracil damage-detection mechanism of UNGs.