A clue to evolution

After 16 years of research, Yale scientists have produced the first images of a group II intron, a cellular molecule whose ancestor may have opened the door to the evolution of higher organisms.

Anna Marie Pyle, Ph.D., professor of molecular biophysics and biochemistry, and her team crystallized the intron of a salt-tolerant bacterium that lives in the Sea of Japan. High-resolution images of the crystal, which appeared in Science in April, support the hypothesis that the intron shares a close evolutionary heritage with the human spliceosome, a complex molecular machine found in higher organisms that allows many proteins to be made from one stretch of the genome.

“The molecules showed us their structure, their active site and their activity,” said Pyle. “We were even able to visualize their associated ions.” Pyle hopes the introns may be developed into agents for gene therapy.