Public Release: 


Van Andel Research Institute


IMAGE: This is the MBH structure. view more 

Credit: Huilin Li, Ph.D., Michael W.W. Adams & Hongjun Yu, Ph.D.

GRAND RAPIDS, Mich., and ATHENS, Ga. (May 10, 2018) -- Ancient microbes that thrive in some of the world's most extreme environments and modern-day humans have more in common than meets the eye -- namely, they both respire and conserve energy using a similar molecular mechanism, one that has adapted to changing environmental conditions over billions of years.


"Nature is really good at finding molecules that work and then modifying them and using them over and over again. This is a prime example," said Michael W.W. Adams, Ph.D., a UGA Distinguished Research and Georgia Power Professor who has been studying MBH for 20 years. "Knowing the structure of MBH provides us with new insights into how Complex I evolved and how it might work."

Almost all life on Earth relies on respiration, which converts electrical energy into a usable, chemical form. MBH and Complex I are important parts of this process; however, until now, the evolutionary connection between them was unclear. MBH's structure also illustrates a mechanism for transducing electrical energy into chemical energy that is simpler than that in Complex I.

"The determination of MBH's structure fills in some important missing pieces that reveal how life adjusted to sweeping changes in the environment throughout the millennia," said Huilin Li, Ph.D., a professor in VARI's Center for Epigenetics and co-senior author on the study. "This solves a fundamental, longstanding mystery in biology."



"It is amazing to see these two distantly related systems reorganize their shared elements to adjust to their different living conditions," said Hongjun Yu, Ph.D., the study's first author and a research scientist in Li's lab. "It looks as if nature is playing with its own building blocks."


MBH was visualized using VARI's high-powered Titan Krios cryo-electron microscope (cryo-EM), which is capable of imaging molecules 1/10,000th the width of a human hair. The Institute's Krios is one of fewer than 120 such microscopes in the world.







