In 1998 , despite barriers to the structural study of integral membrane proteins that had thwarted most attempts for decades , MacKinnon and colleagues determined the three-dimensional molecular structure of a potassium channel from an actinobacteria , `` Streptomyces lividans '' , utilizing X-ray crystallography .
In 1998 , despite barriers to the structural study of integral membrane proteins that had stopped most attempts for decades , MacKinnon and colleagues determined the three-dimensional molecular structure of a potassium channel from bacteria utilizing X-ray crystallography .