Crystal Structures of the structure-selective nuclease Mus81-Eme1 bound to flap DNA substrates

The Mus81-Eme1 complex is a structure-selective endonuclease with a critical role in the resolution of recombination intermediates during DNA repair after interstrand cross-links, replication fork collapse, or double-strand breaks. To explain the molecular basis of 3 ' flap substrate recognition and cleavage mechanism by Mus81-Eme1, we determined crystal structures of human Mus81-Eme1 bound to various flap DNA substrates. Mus81-Eme1 undergoes gross substrate-induced conformational changes that reveal two key features: (i) a hydrophobic wedge of Mus81 that separates pre- and post-nick duplex DNA and (ii) a 5 ' end binding pocket that hosts the 5 ' nicked end of post-nick DNA. These features are crucial for comprehensive protein-DNA interaction, sharp bending of the 3 ' flap DNA substrate, and incision strand placement at the active site. While Mus81-Eme1 unexpectedly shares several common features with members of the 5 ' flap nuclease family, the combined structural, biochemical, and biophysical analyses explain why Mus81-Eme1 preferentially cleaves 3 ' flap DNA substrates with 5 ' nicked ends.X11119Ysciescopu

AC susceptibility and 51^{51}V NMR study of MnV2_2O4_4

We report $^{51}$V zero-field NMR of manganese vanadate spinel of MnV$_2$O$_4$, together with both ac and dc magnetization measurements. The field and temperature dependence of ac susceptibilities show a reentrant-spin-glass-like behavior below the ferrimagnetic(FEM) ordering temperature. The zero-field NMR spectrum consists of multiple lines ranging from 240 MHz to 320 MHz. Its temperature dependence reveals that the ground state is given by the simultaneous formation of a long-range FEM order and a short-range order component. We attribute the spin-glass-like anomalies to freezing and fluctuations of the short-range ordered state caused by the competition between spin and orbital ordering of the V site

The first generation of a BAC-based physical map of Brassica rapa

<p>Abstract</p> <p>Background</p> <p>The genus <it>Brassica </it>includes the most extensively cultivated vegetable crops worldwide. Investigation of the <it>Brassica </it>genome presents excellent challenges to study plant genome evolution and divergence of gene function associated with polyploidy and genome hybridization. A physical map of the <it>B. rapa </it>genome is a fundamental tool for analysis of <it>Brassica </it>"A" genome structure. Integration of a physical map with an existing genetic map by linking genetic markers and BAC clones in the sequencing pipeline provides a crucial resource for the ongoing genome sequencing effort and assembly of whole genome sequences.</p> <p>Results</p> <p>A genome-wide physical map of the <it>B. rapa </it>genome was constructed by the capillary electrophoresis-based fingerprinting of 67,468 Bacterial Artificial Chromosome (BAC) clones using the five restriction enzyme SNaPshot technique. The clones were assembled into contigs by means of FPC v8.5.3. After contig validation and manual editing, the resulting contig assembly consists of 1,428 contigs and is estimated to span 717 Mb in physical length. This map provides 242 anchored contigs on 10 linkage groups to be served as seed points from which to continue bidirectional chromosome extension for genome sequencing.</p> <p>Conclusion</p> <p>The map reported here is the first physical map for <it>Brassica </it>"A" genome based on the High Information Content Fingerprinting (HICF) technique. This physical map will serve as a fundamental genomic resource for accelerating genome sequencing, assembly of BAC sequences, and comparative genomics between <it>Brassica </it>genomes. The current build of the <it>B. rapa </it>physical map is available at the <it>B. rapa </it>Genome Project website for the user community.</p

Genetic diversity of Imjin virus in the Ussuri white-toothed shrew (Crocidura lasiura) in the Republic of Korea, 2004-2010

Recently, Imjin virus (MJNV), a genetically distinct hantavirus, was isolated from lung tissues of the Ussuri white-toothed shrew (Crocidura lasiura) captured near the demilitarized zone in the Republic of Korea. To clarify the genetic diversity of MJNV, partial M- and L-segment sequences were amplified from lung tissues of 12 of 37 (32.4%) anti-MJNV IgG antibody-positive Ussuri white-toothed shrews captured between 2004 and 2010. A 531-nucleotide region of the M segment (coordinates 2,255 to 2,785) revealed that the 12 MJNV strains differed by 0-12.2% and 0-2.3% at the nucleotide and amino acid levels, respectively. A similar degree of nucleotide (0.2-11.9%) and amino acid (0-3.8%) difference was found in a 632-nucleotide length of the L segment (coordinates 962 to 1,593) of nine MJNV strains. Phylogenetic analyses, based on the partial M and L segments of MJNV strains generated by the neighbor-joining and maximum likelihood methods, showed geographic-specific clustering, akin to the phylogeography of rodent-borne hantaviruses

Genome-wide comparative analysis of the Brassica rapa gene space reveals genome shrinkage and differential loss of duplicated genes after whole genome triplication

Euchromatic regions of the Brassica rapa genome were sequenced and mapped onto the corresponding regions in the Arabidopsis thaliana genome

Hemorrhagic Fever with Renal Syndrome in 4 US Soldiers, South Korea, 2005

Four US soldiers acquired hemorrhagic fever with renal syndrome while training near the Demilitarized Zone, South Korea, in 2005. Hantaan virus sequences were amplified by reverse transcription–PCR from patient serum samples and from lung tissues of striped field mice (Apodemus agrarius) captured at training sites. Epidemiologic investigations specified the ecology of possible sites of patient infection

Chylous Leakage: A Rare Complication after Axillary Lymph Node Dissection in Breast Cancer and Surgical Management

Chylous leakage is an extremely rare complication of surgery for breast cancer. We experienced a case of chylous leakage after axillary lymph node dissection. A 38-year-old woman with invasive ductal carcinoma in the left breast underwent a modified radical mastectomy after four cycles of neoadjuvant chemotherapy. The postoperative serosanguinous drainage fluid became "milky" on the fourth postoperative day. After trying conservative management, we re-explored the axilla and ligated the lymphatic trunk. Although the success of many cases supports conservative management, timely surgical intervention represents an alternative in cases where leakage persists or where the output is high

Sismicità all’Etna dal 1989 al 2010: evidenze sull’evoluzione spazio-temporale dell’attività sismica

Il Monte Etna, uno dei più attivi vulcani basaltici tra i più monitorati al mondo, è sede di una notevole attività sismica e vulcanica. Esso è ubicato in Sicilia orientale in un complesso quadro geodinamico, dove le principali strutture tettoniche regionali giocano un ruolo chiave nei processi dinamici del vulcano. La sismicità dell’Etna si manifesta con un elevato rate di terremoti di bassa e moderata energia che, a volte, a causa dell’estrema superficialità della sorgente, provocano danni ai centri abitati prossimi all’area epicentrale. Il monitoraggio sistematico dell’attività sismica etnea è effettuato sin dal 1989, mediante una rete sismica locale permanente che nel tempo è stata oggetto di importanti miglioramenti. La prima configurazione di rete era costituita da circa 10 stazioni analogiche con sensori a corto periodo gestita dall’Istituto Internazionale di Vulcanologia (IIV-CNR). Nel 1994, una rete sismica costituita da circa 40 stazioni (analogiche con sensori a corto periodo) fu installata sull’Etna nell’ambito del Progetto Poseidon. Nel 2001, le reti gestite dall’IIV-CNR e dal Progetto Poseidon confluirono nell’Istituto Nazionale di Geofisica e Vulcanologia (INGV); attualmente la rete sismica, costituita da circa 50 stazioni digitali equipaggiate con sismometri broadband a tre componenti, è gestita dalla Sezione di Catania dell’INGV. Nel periodo 1989-1999, il catalogo dei terremoti risulta costituito da circa 2000 eventi con soglia di completezza per magnitudo pari a 2.0; dal 1999 ad oggi contiene circa 6000 terremoti con soglia di completezza per magnitudo 1.5. La capacità di detezione della rete è migliorata nel tempo permettendo di registrare e localizzare anche gli eventi meno energetici (M≥1.0). In questo lavoro, vengono presentati i caratteri predominanti della sismicità etnea negli ultimi 20 anni, con un maggiore dettaglio della distribuzione spazio-temporale della sismicità verificatasi dal 1999. L’analisi della attività sismica rappresenta un utile strumento per l’interpretazione delle dinamiche che hanno contraddistinto numerose ed importanti eruzioni (2001, 2002-03, 2004, 2006, 2008-09). In particolare, la variazione del rilascio energetico della sismicità ha contribuito in maniera significativa ad identificare i probabili processi geodinamici legati alla ricarica del sistema magmatico del vulcano. La distribuzione spaziale della sismicità ha consentito di evidenziare inoltre l’esistenza di diverse aree sismogenetiche caratterizzate da un differente rate sismico, profondità focali e cinematica delle strutture associate. Infine, osservando le caratteristiche della sismicità nel lungo periodo, differenti settori del vulcano sono risultati maggiormente attivi in relazione ai più importanti recenti eventi eruttivi

Overexpression of arabidopsis YUCCA6 in potato results in high-auxin developmental phenotypes and enhance

Indole-3-acetic acid (IAA), a major plant auxin, is produced in both tryptophan-dependent and tryptophanindependent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid (IPA) by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC (Solanum tuberosum YUCCA) genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences: FATGY motif, FMO signature sequence, and FAD-binding and NADPbinding sequences. In addition, five genes were found with ~50% amino acid sequence identity to Arabidopsis tryptophan aminotransferases. Transgenic potato (Solanum tuberosum cv. Jowon) constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a functional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment. © 2012 The Author