Searching for smart, safe news you can TRUST?

Support safe, smart, REAL journalism. Sign up for our Axios AM & PM newsletters and get smarter, faster.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Performing a CRISPR-Cas9 process. Photo: Gregor Fischer/picture alliance via Getty Images

Scientists were able to alter an enzyme from a thermophilic bacteria so it can be used by CRISPR to edit human genes more effectively, per a study published in Nature Communications on Tuesday.

Why it matters: CRISPR is powerful but can sometimes cause large deletions or move DNA inadvertently. To make it more precise, researchers have been testing hundreds of new enzymes. Study author Feng Zhang says Cas12b's small size and precise targeting will enable it to be used for in vivo applications in primary human cells.

Background: The Cas12b family of enzymes was first brought to attention in 2015, and led to some recent studies (here and here) better defining their uses and limitations.

  • This study's enzyme, called BhCas12b, is from a bacterium (Bacillus hisashii) that lives in hot environments like geysers and volcanoes.
  • The main problem of using Cas12b was its temperature restriction. In its natural state, it's ineffective as a gene-editing tool at the lower body temperature of humans.

What they did: Zhang, who is a core institute member of the Broad Institute of MIT and Harvard, tells Axios that the team studied its three dimensional shape and made changes they predicted would make it more active at lower temperatures.

What they found: With the modifications and its naturally small size, BhCas12b was able to cut both DNA strands without many off-targets, Zhang says, and can efficiently edit genomes in primary human T cells.

"The size of the protein matters because for many applications, it needs to be packaged into a minimal viral vector for delivery. Viruses naturally have a restricted cargo capacity, so a smaller genome editing enzyme is beneficial."
— Feng Zhang

Outside perspective: Scientists not involved in this study say it shows Cas12b can be altered to become a promising CRISPR enzyme, but note that this small study should be validated with further research.

  • Ilya Finkelstein, assistant professor of molecular biology at the University of Texas-Austin, says he found it interesting they took a protein not normally functional in humans and engineered it to work. "There are hundreds of variants of these proteins. ... This suggests that the CRISPR toolkit will continue to grow."
  • Konstantin Severinov, principal investigator for Rutgers' Waksman Institute of Microbiology, says: "The study shows that Cas12b ... can be used, after some clever laboratory tweaking, for genomic editing in human cells. It may offer some advantages during editing compared to Cas9 and Cas12a."

Between the lines: Most CRISPR testing uses the first discovered enzyme, CAS9, so it's unlikely there will be a large shift to other enzymes soon, at least until they are proven to be safe and become cheaper.

  • "The one that is used by most people [Cas9] is not the best, it was simply the first to be characterised and reduced to practice. So there is clear room for improvement and many people are looking for better ones," Severinov says.
  • "[T]ime will tell whether Cas12b can take the crown from Cas9," Finkelstein adds.

Go deeper:

Go deeper

12 mins ago - Politics & Policy

Biden: "We will manage the hell out of" vaccine distribution

Joe Biden. Photo: Chip Somodevilla / Getty Images

President-elect Joe Biden promised to invoke the Defense Production Act to increase vaccine manufacturing, as he outlined a five-point plan to administer 100 million COVID-19 vaccinations in the first months of his presidency.

Why it matters: With the Center for Disease Control and Prevention warning of a more contagious variant of the coronavirus, Biden is trying to establish how he’ll approach the pandemic differently than President Trump.

A new Washington

Photo: Stefani Reynolds/Getty Image

D.C. Mayor Muriel Bowser said Friday that the city should expect a "new normal" for security — even after President-elect Biden's inauguration.

The state of play: Inaugurations are usually a point of celebration in D.C., but over 20,000 troops are now patrolling Washington streets in an unprecedented preparation for Biden's swearing-in on Jan. 20.

Mike Pence calls Kamala Harris to offer congratulations and help

Mike Pence. Photo: Chip Somodevilla via Getty

Vice President Mike Pence called Vice President-elect Kamala Harris on Thursday to congratulate her and offer assistance in the transition, the New York Times first reported.

Why it matters: The belated conversation came six days before the inauguration after a contentious post-election stretch. President Trump has neither spoken with President-elect Joe Biden, nor explicitly conceded the 2020 election.