An international team led by Lund University and the University of New South Wales has built an artificial protein motor that takes controlled, directional steps along a strand of DNA, a feat that has eluded synthetic biology for years. The work, published in Nature Nanotechnology, shows that artificial motors can be built from the same molecular building blocks used by nature's own, which power everything from cell division to muscle movement with a precision researchers have long studied but struggled to reproduce.
“Just as the steam engine laid the foundation for today’s mechanical engines, this breakthrough could mark the starting point for a deeper understanding of biology’s own motors,” says Heiner Linke, lead author of the study.
Named Tumbleweed, the motor advances by cycling through three DNA-binding “feet,” each attaching to a specific sequence on the track. Researchers steer its movement, including both timing and direction, by adjusting the surrounding chemical conditions. “With Tumbleweed, we are gaining insight into the fundamental principles governing biological protein motors and how we may eventually come closer to matching nature’s performance,” Linke says.
For comparison, Linke points to two natural motors already at work in the body: myosin, which converts chemical energy into muscle force and supports cell division, and kinesin, which ferries signaling molecules through cells. Proteins make attractive but difficult material to engineer, he notes: “Proteins are far more complex than other molecular building blocks and therefore offer much greater possibilities. But that same complexity also makes them more challenging to work with.”
Recent progress in protein design has mostly produced fixed, single-purpose structures. Tumbleweed instead shows that a protein structure can move and be steered from outside the system, a capability the team sees as a foundation rather than an endpoint. Their next target is a motor that no longer needs external prompting and can move on its own using chemical fuel.
Linke likens the current stage to early childhood development: “Right now, we have a one-year-old who can take a few steps while holding someone’s hand. The next stage is learning to walk independently. After that, we can start thinking about athletics, marathons and the Olympics.”
“Just as the steam engine laid the foundation for today’s mechanical engines, this breakthrough could mark the starting point for a deeper understanding of biology’s own motors,” says Heiner Linke, lead author of the study.
Named Tumbleweed, the motor advances by cycling through three DNA-binding “feet,” each attaching to a specific sequence on the track. Researchers steer its movement, including both timing and direction, by adjusting the surrounding chemical conditions. “With Tumbleweed, we are gaining insight into the fundamental principles governing biological protein motors and how we may eventually come closer to matching nature’s performance,” Linke says.
For comparison, Linke points to two natural motors already at work in the body: myosin, which converts chemical energy into muscle force and supports cell division, and kinesin, which ferries signaling molecules through cells. Proteins make attractive but difficult material to engineer, he notes: “Proteins are far more complex than other molecular building blocks and therefore offer much greater possibilities. But that same complexity also makes them more challenging to work with.”
Recent progress in protein design has mostly produced fixed, single-purpose structures. Tumbleweed instead shows that a protein structure can move and be steered from outside the system, a capability the team sees as a foundation rather than an endpoint. Their next target is a motor that no longer needs external prompting and can move on its own using chemical fuel.
Linke likens the current stage to early childhood development: “Right now, we have a one-year-old who can take a few steps while holding someone’s hand. The next stage is learning to walk independently. After that, we can start thinking about athletics, marathons and the Olympics.”