DNA Origami Reveals Molecular Motor Movements

A recent study from Harvard University produced the first recording of the rotational steps of a molecular motor as it moved from one DNA base pair to another. These researchers created ORBIT, origami-rotor-based imaging and tracking, to see molecular motors in action. Molecular motors are crucial in the human body for events such as muscle contraction and repair, replication or transcription of DNA. 

Photo from Irish Times - Why did I risk my privacy with home DNA testing

To study the molecular motors in motion, researchers wanted to focus on the twisting movement of a strand of DNA. First, they glued a DNA interacting motor to a strong support. The motor then had to rotate the helix of DNA in order to travel from one base pair to the next. However, every time a motor moves across one base pair, the rotation of the helix shifts the DNA. This shift is so tiny, it can’t be observed under a light microscope. 

Pens lying in the shape of helicopter propellers sparked a genius idea. If the spinning DNA could move at the same rate as the helix and the molecular motor, researchers could capture the movement on camera. DNA origami was used to construct such propellers. More specifically the team wove approximately 200 pieces of DNA into a propeller shape that was 160 nanometers in length. The propeller was attached a standard double helix on one end and a molecular motor that unzips DNA (RECBCD) at the other end.

“No one had seen this protein actually rotate the DNA because it moves super-fast,” Pallav Kosuri from the Zhuang Lab admitted. The molecular motor can travel across hundreds of base pairs of DNA in just a few seconds. With the origami propellers and a high speed camera, the team could finally record the movements. The technology that ORBIT will allow and inspire is astonishing. Finally, researchers are able to study such tiny processes that are so important. I think ORBIT and further studies, can allow scientists, especially geneticists, to study specific pieces of DNA or genes. In my opinion, this process can allow researchers to be more accurate in concluding the cause of many diseases and disorders. 

Ancient Organs

Researchers may have discovered the 700 million year old mutation that allowed for the production of lungs, forelimbs, and inner ear.  In an article found on Science Daily, many organs in vertebrates have been linked back to multiple mutations.  The regulatory protein called ESRP acts as a molecular switch to splice and rejoin genes, they are also involved with morphogenesis and cell to cell interactions which generate different protein variants.  At first the evolutionary significance of these genes were not known, however until recently it is thought that this group of regulatory proteins mutated and began to create the proteins assigned for the lungs and other organs specific to the vertebrates.
This article is interesting because it shows what could have caused the mutation resulting in the coding for the inner organs.  The evolutionary significance for the ESRP would make sense for it to be important for our history but there had to have been something else alongside this mutation to correct the formation and placement over time for the organs such as the lungs.