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Planet's close dance speeds star's spin
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in Brief Bone hormone rejuvenates muscle
Ancestor of all bacteria spent its time in a hot bath THE ancestor of all bacteria may have had sophisticated enzymes 3.4 billion years ago – just 600 million years after the origin of life on Earth. That’s also about a billion years before many people thought the enzymes evolved. Modern enzymes fit the molecules they react with like a lock to a key. In contrast, the earliest enzymes were sloppier and less specific. Now Reinhard Sterner at the University of Regensburg in Germany and his colleagues have looked at an enzyme called tryptophan synthase. It aids the creation of an amino acid crucial to bacteria, archaea, plants and fungi,
so a form of it has probably been around for a long time. They fed the gene sequences that code for the enzyme in modern bacteria and archaea into a computer program that searched for similarities. They then ran simulations of what the DNA sequence might have been before the groups split. The team reconstructed the most probable sequence and inserted the gene into E. coli cells, which churned out an enzyme that behaved much like the modern versions (Cell Chemical Biology, doi.org/bjzk). The enzyme kept its structure up to about 70 °C. “You can infer with strong confidence that the organism lived in a hot environment,” says Mathieu Groussin at the Massachusetts Institute of Technology. This adds weight to hypotheses about the first bacteria living in hot water, he adds.
Planet’s close dance speeds star’s spin A FARAWAY planet locked in a close dance with its star is making its partner spin faster. The orbital waltz, which mirrors that of Earth and its moon, could be the best lab yet for studying how planets affect their stars and vice versa. Astronomers using the Hungarian-made Automated Telescope Network-South Exoplanet Survey spotted the big, gassy world around a star dubbed
HATS-18, which is almost identical in size and temperature to our sun. It’s so close to the star that it orbits in just 20 hours. Kaloyan Penev of Princeton University and his colleagues noticed the star was spinning too fast for its size and age, meaning something was causing it to rotate faster. They found that the planet is moving ever closer to the star, speeding it up through a process
known as tidal dissipation (arxiv.org/abs/1606.00848). The opposite happens in the Earth-moon system: the moon is moving away from Earth and Earth’s spin is slowing down, with days gradually getting longer. The pronounced effect in HATS-18 means researchers will be able to use the system to study tidal dissipation elsewhere in the cosmos, from distant star systems to the interaction of Jupiter and its moons, says Penev.
WIND back the clock. We’ve found a hormone that can rejuvenate the muscles of elderly mice. Osteocalcin – a hormone secreted by bone – boosts the ability of muscles to burn fuel and generate energy, Gerard Karsenty of Columbia University and his colleagues discovered. When the team injected the hormone into old mice, the animals were able to run just as far as their younger counterparts, despite being up to a year older – a long time in mouse years. Old mice that did not receive the hormone ran about half as far (Cell Metabolism, DOI: 10.1016/j.cmet.2016.05.004). “It was extremely surprising,” says Karsenty. Osteocalcin levels decline with age in both mice and humans, and the team now plans to test whether the hormone can improve muscle function in people too.
Space elevators can’t work BYE-BYE, space elevator. Carbon nanotubes are famed for being super-strong. But just one out-ofplace atom seems enough to cut their strength by more than half. That means one of the more outlandish applications – a space elevator between Earth and a satellite – might be doomed. Feng Ding of the Hong Kong Polytechnic University and his colleagues have simulated carbon nanotubes in which a single atom is out of place, creating a kink in the tube. They found the kink acts as a weak point, easily snapping the normally strong bonds between the carbon atoms. Once this happens, the bonds in the adjacent hexagons also break, unzipping the entire tube (ACS Nano, doi.org/bjzj). 18 June 2016 | NewScientist | 15
in Brief Bone hormone rejuvenates muscle
Ancestor of all bacteria spent its time in a hot bath THE ancestor of all bacteria may have had sophisticated enzymes 3.4 billion years ago – just 600 million years after the origin of life on Earth. That’s also about a billion years before many people thought the enzymes evolved. Modern enzymes fit the molecules they react with like a lock to a key. In contrast, the earliest enzymes were sloppier and less specific. Now Reinhard Sterner at the University of Regensburg in Germany and his colleagues have looked at an enzyme called tryptophan synthase. It aids the creation of an amino acid crucial to bacteria, archaea, plants and fungi,
so a form of it has probably been around for a long time. They fed the gene sequences that code for the enzyme in modern bacteria and archaea into a computer program that searched for similarities. They then ran simulations of what the DNA sequence might have been before the groups split. The team reconstructed the most probable sequence and inserted the gene into E. coli cells, which churned out an enzyme that behaved much like the modern versions (Cell Chemical Biology, doi.org/bjzk). The enzyme kept its structure up to about 70 °C. “You can infer with strong confidence that the organism lived in a hot environment,” says Mathieu Groussin at the Massachusetts Institute of Technology. This adds weight to hypotheses about the first bacteria living in hot water, he adds.
Planet’s close dance speeds star’s spin A FARAWAY planet locked in a close dance with its star is making its partner spin faster. The orbital waltz, which mirrors that of Earth and its moon, could be the best lab yet for studying how planets affect their stars and vice versa. Astronomers using the Hungarian-made Automated Telescope Network-South Exoplanet Survey spotted the big, gassy world around a star dubbed
HATS-18, which is almost identical in size and temperature to our sun. It’s so close to the star that it orbits in just 20 hours. Kaloyan Penev of Princeton University and his colleagues noticed the star was spinning too fast for its size and age, meaning something was causing it to rotate faster. They found that the planet is moving ever closer to the star, speeding it up through a process
known as tidal dissipation (arxiv.org/abs/1606.00848). The opposite happens in the Earth-moon system: the moon is moving away from Earth and Earth’s spin is slowing down, with days gradually getting longer. The pronounced effect in HATS-18 means researchers will be able to use the system to study tidal dissipation elsewhere in the cosmos, from distant star systems to the interaction of Jupiter and its moons, says Penev.
WIND back the clock. We’ve found a hormone that can rejuvenate the muscles of elderly mice. Osteocalcin – a hormone secreted by bone – boosts the ability of muscles to burn fuel and generate energy, Gerard Karsenty of Columbia University and his colleagues discovered. When the team injected the hormone into old mice, the animals were able to run just as far as their younger counterparts, despite being up to a year older – a long time in mouse years. Old mice that did not receive the hormone ran about half as far (Cell Metabolism, DOI: 10.1016/j.cmet.2016.05.004). “It was extremely surprising,” says Karsenty. Osteocalcin levels decline with age in both mice and humans, and the team now plans to test whether the hormone can improve muscle function in people too.
Space elevators can’t work BYE-BYE, space elevator. Carbon nanotubes are famed for being super-strong. But just one out-ofplace atom seems enough to cut their strength by more than half. That means one of the more outlandish applications – a space elevator between Earth and a satellite – might be doomed. Feng Ding of the Hong Kong Polytechnic University and his colleagues have simulated carbon nanotubes in which a single atom is out of place, creating a kink in the tube. They found the kink acts as a weak point, easily snapping the normally strong bonds between the carbon atoms. Once this happens, the bonds in the adjacent hexagons also break, unzipping the entire tube (ACS Nano, doi.org/bjzj). 18 June 2016 | NewScientist | 15