Rockefeller said to me, in essence, that they like scientists who take risks and they were willing to take me on in that attempt. It is nice when an institution can offer that kind of support. In addition, it has been tremendously helpful to my research to be able to confer with the experts at Rockefeller in related fields. At Rockefeller, MacKinnon learned X-ray crystallography, a skill he realized he would need in order to directly visualize a potassium channel in a way that previous experiments could not accomplish. This newly acquired proficiency led to the first structure of the potassium channel, which was published in Science in April 1998.
Many questions remain unanswered.
MacKinnon suspects that ions in the pore interact with one another through the structure of the protein, but establishing this will require higher-resolution data. The ability to actually look at ion channel structures has already begun to stimulate new directions in ion channel research. His laboratory recently solved the structure of the channel's Beta subunit, which regulates when the channel opens and closes. These new discoveries keep him fascinated and looking forward to what lies ahead in the field he so enjoys. If you tackle a problem and keep working on it, eventually you will find some kind of outcome.