Ubiquitin-mediated proteolysis is the key to cell cycle control. Anaphase-promoting complex/cyclosome (APC) is a ubiquitin ligase that targets cyclin B and factors regulating sister chromatid separation for proteolysis by the proteasome and, consequently, regulates metaphase-anaphase transition and exit from mitosis. Here we report that Cdc2-cyclin B-activated Polo-like kinase (Plk) specifically phosphorylates at least three components of APC and activates APC to ubiquitinate cyclin B in the in vitro-reconstituted system. Conversely, protein kinase A (PKA) phosphorylates two subunits of APC but suppresses APC activity. PKA is superior to Plk in its regulation of APC, and Plk activity peaks whereas PKA activity is falling at metaphase. These results indicate that Plk and PKA regulate mitosis progression by controlling APC activity.

Summary 1.Recent findings indicate that the interactions among CO 2 , temperature and water can be substantial, and that the combined effects on the biological systems of several factors may not be predicted from experiments with one or a few factors. Therefore realistic multifactorial experiments involving a larger set of main factors are needed. 2. We describe a new Danish climate change-related field scale experiment, CLIMAITE, in a heath/ grassland ecosystem. CLIMAITE is a full factorial combination of elevated CO 2 , elevated temperature and prolonged summer drought. The manipulations are intended to mimic anticipated major environmental changes at the site by year 2075 as closely as possible. The impacts on ecosystem processes and functioning (at ecophysiological levels, through responses by individuals and communities to ecosystem-level responses) are investigated simultaneously. 3. The increase of [CO 2 ] closely corresponds with the scenarios for year 2075, while the warming treatment is at the lower end of the predictions and seems to be the most difficult treatment to increase without unwanted side effects on the other variables. The drought treatment follows predictions of increased frequency of drought periods in summer. The combination of the treatments does not create new unwanted side effects on the treatments relative to the treatments alone.

Complete genome sequence of the industrial bacterium Bacillus licheniformis and comparisons with closely related Bacillus species

Bacillus licheniformis is a Gram-positive, spore-forming soil bacterium that is used in the biotechnology industry to manufacture enzymes, antibiotics, biochemicals and consumer products. This species is closely related to the well studied model organism Bacillus subtilis, and produces an assortment of extracellular enzymes that may contribute to nutrient cycling in nature.

The 2,5B conformation found for the alpha-linked xylobiosyl-enzyme intermediate of Xyl11, unlike the 4C1 chair conformation observed for other systems, is consistent with the stereochemical constraints required of the oxocarbenium-ion-like transition state. Comparison of the Xyl11 covalent glycosyl-enzyme intermediate with the equivalent structure for the related family 12 endoglucanase, CelB, from Streptomyces lividans reveals the likely determinants for substrate specificity in this clan of glycoside hydrolases.

The plant cell wall is a complex material in which the cellulose microfibrils are embedded within a mesh of other polysaccharides, some of which are loosely termed "hemicellulose." One such hemicellulose is xyloglucan, which displays a ␤-1,4-linked D-glucose backbone substituted with xylose, galactose, and occasionally fucose moieties. Both xyloglucan and the enzymes responsible for its modification and degradation are finding increasing prominence, reflecting both the drive for enzymatic biomass conversion, their role in detergent applications, and the utility of modified xyloglucans for cellulose fiber modification. Here we present the enzymatic characterization and three-dimensional structures in ligandfree and xyloglucan-oligosaccharide complexed forms of two distinct xyloglucanases from glycoside hydrolase families GH5 and GH12. The enzymes, Paenibacillus pabuli XG5 and Bacillus licheniformis XG12, both display open active center grooves grafted upon their respective (␤/␣) 8 and ␤-jelly roll folds, in which the side chain decorations of xyloglucan may be accommodated. For the ␤-jelly roll enzyme topology of GH12, binding of xylosyl and pendant galactosyl moieties is tolerated, but the enzyme is similarly competent in the degradation of unbranched glucans. In the case of the (␤/␣) 8 GH5 enzyme, kinetically productive interactions are made with both xylose and galactose substituents, as reflected in both a high specific activity on xyloglucan and the kinetics of a series of aryl glycosides. The differential strategies for the accommodation of the side chains of xyloglucan presumably facilitate the action of these microbial hydrolases in milieus where diverse and differently substituted substrates may be encountered.

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ABSTRACT. The humoral immune response to Egtved virus, the causative agent of viral haemorrhagic septicaemia (VHS) in rainbow trout Oncorhynchus mykiss, was investigated by means of the enzymelinked immunosorbent assay (ELISA), immunofluorescence (IF), a n d the 50 'X plaque neutralization test (50°/"PNT). Sera from fish immunized with virus under aquarium conditions as well a s sera collected from fish in farms with different VHS status were included In the experiments. ELISA proved to b e more sensitive and less time-and material-consuming than either IF or 50°/~PNT Using Elisa, antibody to Egtved virus was found in 54 %I of fish from infected trout farms examined w h~l e only 16 % were positive by 50°/r,PNT The IF test had a sensitivity close to that of ELISA, but was less suitable for examination of large numbers of sera. Non-neutralizing antibodies tend to perslst longer after VHS infection than neutralizing antibodies. The kinetics of the antibody response was close to that prev~ously published. No anamnestic immune response was observed with any of the tests. We conclude that our ELISA is well suited for VHS surveillance.

The humoral immune response of trout to Egtved virus (VHS) was examined by means of a 50 % plaquc neutralization test with complement addition. The test, wich has been adapted for use in microtitn plates, is documented with re ard to specificity and sensitivity.Eight weeks after VHS inkction by cohabitation at 13 "C neutralizing antibody could be detected ir 100 YO of individually tagged experimental trout. Maximal titres of 10240 were found six weeks aftei infection. In 36 % of the trout antibody was still detectable one year after infection.Neutralizing antibody could be detected also in trout infected with V H S under trout farm conditions. The percentage of positive sera ranged from 4 to 56. Zusammenfassung Nachweis von neutralisierenden Antikorpem gegen das Egtved Virus bei Regenbogenforellen (Salmo gairdneri) mittels der Pkqueneutralisationsmethode unter KomplementzusatzDie humorale Immunanwort der Forellen gegen das Egrved Virus (VHS) ist mittels der 50 %-Plaqueneutralisationsmethode unter Komplementzusatz ermittelt worden.Die Methode (hier zum Mikrotitersystem adaptiert) wurde im Hinblick auf die Spezifizitat und die Empfindlichkeit untersucht.Acht Wochen nach der VHS Infektion durch Kohabitation bei 13 "C konnten neutralisierende Antikorper bei 100 % der individuell markierten Forellen nach ewiesen werden. Maximale Titerwerte von 1 : 10240 wurden sechs Wochen nach der Infektion ermitteft. Bei 36 % der Forellen konnten noch ein Jahr nach der Infektion Antikorper nachgewiesen werden.Neutralisierende Antikorper waren auch bei Forellen nachweisbar, die unter teichwirtschaftlichen Bedingungen infiziert worden waren. Unter diesen Forellen wurden zwischen 4 % und 56 % antikorperpositive Fische gefunden. Rbumi Demonstration des anticorps neutralisants contre le virus d'Egtved chez la truite arc-en-riel (Salmo gairdneri) par I'ipreuve de neutralisation despkzques avec I'addition de complimentLa riponse sirique immunitaire de la m i t e arc-en-ciel aprks I'infection avec le virus d'Egtved (SHV) 1 i t i Cxaminie par I'epreuve de neutralisation des plaques avec I'addition de compliment. Le test, adapt6 1 un systkme de microtitre, est documenti par rapport a sa spicificiti et a sa sensitiviti.Huit semaines aprks 1' infection du virus d'Egtved par cohabitation h 13 "C, des anticorps neutralisants pouvaient Crre dimontris dans 100 ' 3' 0 des poissons individuellement numiroti. Des titres maximales de 10240 itaient dimontrables six semaines apres I'infection. Chez 36 YO des truites, des anticorps itaient encore dimontrables un an apres I'infection.Des anticorps neutralisants itaient aussi dimontrables dans des truites contagies sous les conditions de pisciculture. Le pourcentage des sira positives se rangeait de 4 156.U.S.