Synthetic human genome discussion blows up on social media

Not content merely to read the genome anymore, some human geneticists also want to write it, synthetically. The idea is intriguing, but the discussions about how it would work recently generated more than a bit of consternation among science reporters, sparking a dustup on social media that have followed the project, which is called HGP 2.0 or HGP-write. HGP 2.0, which is still in its very earliest days, is not currently funded. A recent closed-door session left many wondering just what was so secret about the initial meeting to discuss the project, which was held in mid-May at Harvard University at the behest of geneticist George Church, one of the organizers. Social media abounded with criticism that the event, originally intended to be open to the public and reporters, was closed (to preserve a media embargo on the meeting’s associated Science article, slated to be published in June). The faux pas seemed to raise questions about the group’s intentions among reporters, but that wasn’t the end of the criticism. Even medical professionals who had been invited to the meeting openly questioned its lack of forethought and transparency. Laurie Zoloth, a medical ethicist at Northwestern University, coauthored a commentary critical of the project that was timed to appear on the very day of the May meeting. Appearing on the website of the magazine Cosmos, and coauthored with Drew Endy, a writer for the magazine, the commentary not only argued that any discussion of a synthetic genome should take place in the open but also questioned whether the project should be pursued at all. Instead, they wrote, the next large-scale genome project should be aimed at improving gene transfer technologies and synthetic capabilities at the subgenome level, which would avoid some of the more serious ethical questions now dogging HGP 2.0. —Karyn Hede, News Editor

Reanimated enzyme brought back from evolutionary death

Resurrecting an enzyme lost in the mists of evolutionary time, scientists at the University Regensburg in Germany have revealed that ancient enzymes were hardier than many experts have believed and may have existed in modern form much earlier than is now understood. Reinhard Sterner and his colleagues published data from the reconstructed tryptophan synthase in Cell Chemical Biology in June 2016. The research showed that this early version of an enzyme essential in making the amino acid tryptophan was probably as efficient as modern enzymes and was likely stable in the steamy hot conditions that may have existed early in earth’s history. To reanimate the ancient enzyme, the research team analyzed forms of the enzyme in modern bacteria and archaea and then conducted a computer search for the most probable common ancestral sequence, which would have existed 3.4 billion years ago. They then synthesized the predicted enzyme in Escherichia coli bacteria and evaluated its stability and activity. The enzyme folded similarly to the modern enzyme, worked efficiently, and was stable up to 70 °C. The study suggests that specific and efficient, fully functioning, “modern” enzymes existed much earlier than is currently understood. Given that no DNA survives from billions of years ago, reconstruction of the ancestors of modern enzymes has become a useful strategy to understand evolutionary biochemistry and is challenging prior assumptions about the sophistication of ancient life forms. —Karyn Hede, News Editor