The dextransucrase DSR-OK from the Gram-positive bacterium Oenococcus kitaharae DSM17330 produces a dextran of the highest molar mass reported to date (∼109 g/mol). In this study, we selected a recombinant form, DSR-OKΔ1, to identify molecular determinants involved in the sugar polymerization mechanism and that confer its ability to produce a very-high-molar-mass polymer. In domain V of DSR-OK, we identified seven putative sugar-binding pockets characteristic of glycoside hydrolase 70 (GH70) glucansucrases that are known to be involved in glucan binding. We investigated their role in polymer synthesis through several approaches, including monitoring of dextran synthesis, affinity assays, sugar binding pocket deletions, site-directed mutagenesis, and construction of chimeric enzymes. Substitution of only two stacking aromatic residues in two consecutive sugar-binding pockets (variant DSR-OKΔ1-Y1162A-F1228A) induced quasi-complete loss of very-high-molar-mass dextran synthesis, resulting in production of only 10–13 kg/mol polymers. Moreover, the double mutation completely switched the semiprocessive mode of DSR-OKΔ1 toward a distributive one, highlighting the strong influence of these pockets on enzyme processivity. Finally, the position of each pocket relative to the active site also appeared to be important for polymer elongation. We propose that sugar-binding pockets spatially closer to the catalytic domain play a major role in the control of processivity. A deep structural characterization, if possible with large-molar-mass sugar ligands, would allow confirming this hypothesis.

PREPARATIONS to give out millions of coronavirus vaccines must start now or Scotland risks compounding the economic damage caused by the pandemic, a leading expert has warned.

The Herald is bringing live coronavirus updates and breaking news from Scotland, the UK and the world.

The limited-edition Harley-Davidson Street 750 was launched in India in August 2019 and was costlier than the standard BS4 model by Rs 13,000.

Petrol price is hiked by Rs 1.67 per litre while diesel price is increased by Rs 7.10 per litre in Delhi.

After successfully topping our all-time battery life chart, with the 5,000 mAh pack inside the Realme 6i, which you can read more about here, the Chinese company apparently has its sight set even higher. A TUV certification filing for a particular BLP793 battery pack has now been brought to light. Mainly since its rated capacity is a whopping 6,000 mAh. Well, 5,860mAh, to be precise, with a typical capacity of 6,000 mAh. But, the point stands. Battery certification The jury is now out on which phone we can expect to see this pack in. That's more guess-work than anything else,...

The newly-built church outside Moscow designed to be the main cathedral of the Russian military has been completed and decorated. While its opening was delayed by Covid-19, its final look was revealed on Victory Day.
Read Full Article at RT.com

WBC heavyweight champion Tyson Fury has teased on social media that some "massive" news is soon to be released by his management company, sparking rumors that a title unification bout with Anthony Joshua is just around the corner.
Read Full Article at RT.com

With the latest cut in prices, a 14.2 kg non-subsidised LPG cylinder would cost Rs 581.50, instead of Rs 744 with effect from today.

Petrol, Diesel Price Today:  Prime Minister Narendra Modi’s government late Tuesday evening increased excise duty on petrol by a record Rs 10 per litre, and on diesel by Rs 13 per litre.

Delhi recorded the maximum temperature of 40.9 degrees centigrade on Saturday, the IMD said. Due to the Western Disturbance, the IMD in its weather summary and forecast bulletin predicted isolated to scattered rain over the Western Himalayan region and plains of Northwest India, with peak activity on May 10, 2020.

U.K. electricity from low-carbon sources accounted for almost a quarter of the country’s generation in the fourth quarter as Drax Group Plc converted a second coal-power plant to burn wood.

U.K. electricity from low-carbon sources accounted for almost a quarter of the country’s generation in the fourth quarter as Drax Group Plc converted a second coal-power plant to burn wood.

THERE were mixed reactions, last week, over the transfer of 62 southern police officers from the ranks of Superintendent of Police, SP, to Chief Superintendent of Police, CSP, and including 15 Divisional Police Officers, DPOs, from Delta State Police Command to the northern part of the country.

The post AMID SUSPECTED HERDSMEN ATTACKS: Storm in Delta over mass transfer of police officers appeared first on Vanguard News.

[This Day] Akure -The Ondo State Government yesterday asked all residents that have deceased relations in all government mortuaries in the state to claim and burry them within one month or it would conduct mass burial for the corpses after the ultimatum.

There are plans to bring the bishop's body back to Kenya.

Felipe Massa admitted he made a mistake with tyre strategy during qualifying for the Italian Grand Prix but is expecting to be competitive in Sunday's race

Ferrari's Felipe Massa believes second place would have been within his grasps at the Italian Grand Prix had it not been for a slow pit stop

Tonio Liuzzi believes his first lap clash with Felipe Massa at the Canadian Grand Prix was a racing accident but admitted it cost him dear

Felipe Massa was left to ponder what might have been after two separate racing incidents ruined his chances of a points finish

Michael Schumacher was not penalised for his part in colliding with Felipe Massa while racing for position towards the end of the Canadian Grand Prix

Felipe Massa refused to take the blame for his move on the opening lap that led to his retirement, instead blaming bad luck

Ferrari president Luca di Montezemolo is expecting Felipe Massa to return to form in the final three races and get amongst the five title challengers

Felipe Massa admitted the team has much hard work to do in the weeks ahead if it is to hold onto the lead of the drivers' and constructors' standings

Mass slaughter of poultry was done at a market by the authorities in Shanghai after the H7N9 bird flu virus claimed the lives of five people. The

Gaps in data covering refugees, asylum seekers, migrants and internally displaced populations are endangering the lives and well-being of millions of children on the move, warned five UN and partner agencies today.

Delhi-NCR witnessed a sudden change of weather when the region was hit by a dust storm followed by rain after a sunny morning on Sunday, May 10.

PETER HITCHENS: We will not escape from this misery until the Government has been forced to admit that it made a foolish mistake and over-reacted wildly to Covid-19.

A huge fire has broken out near the Qantas Terminal at Sydney airport.

The Swedish maker, now owned by China's Geely, is driving hard towards electricification (its 'Pure' mode) and to have a plug-in hybrid or fully electric option across its entire range.

Supercar dealer Tom Hartley provides a welcome splash of vibrant colour in our grey corporate landscape as Britain's - and arguably the world's - best-known independent car dealer.

Deputy Premier and Minister for Regional NSW John Barilaro announced the $310million package for drought-affected farmers and communities.

PETER HITCHENS: We will not escape from this misery until the Government has been forced to admit that it made a foolish mistake and over-reacted wildly to Covid-19.

The evidence of the pernicious influence of today's mass-media empires is overwhelming. But, lacking a historical consciousness that includes technology, modern India is thoroughly unprepared to tackle the excesses they promote, says Venkatesh R. Iyer.

Sharjah, May 06: A massive fire was reported in a residential building in AL Nahda in Sharjah on Tuesday. No casualties have been reported and the fire has been put out. The residential tower, Abbco Tower has 56 floors,

Archives, Room Use Only - QC517.V92 1927

Archives, Room Use Only - TK5611.D37 1988

Archives, Room Use Only - KF223.G655 G655 1887

Archives, Room Use Only - CS71.V129 1937

Archives, Room Use Only - CS71.V129 1947

Unprecedented scenes of empty churches emerged from Italy and other countries of the world, as religious leaders found creative ways to address parishioners marking the holiday weekend from the confines of their homes.