Towards a Crystal Structure of the Cystic Fibrosis Transmembrane Conductance Regulator

Susan K. Fetics1,2, Pikyee Ma1,2, Luba Aleksandrov3, Timothy Jensen3 , Cedric Govaerts2, John Riordan3 and Martin Caffrey1

1 Membrane Structural and Functional Biology Group, Schools of Medicine and Biochemistry and Immunology, Trinity College Dublin.

2Laboratory of Structure and Function of Biological Membranes, Center for Structural Biology and Bioinformatics, Université Libre de Bruxelles, Brussels, Belgium.

3 Department of Biochemistry and Biophysics, and Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill.

 

Cystic Fibrosis (CF), a fatal genetic disease affecting predominantly European descendants, has symptoms of poor growth, poor weight gain, infertility, lung disease, intestinal obstruction and untimely death due to respiratory and / or liver failure. An estimated 80,000 people suffer from CF worldwide. The gene responsible for CF codes for the cystic fibrosis transmembrane conductance regulator (CFTR), an integral membrane glycoprotein channel in the plasma membrane of epithelial mammalian cells. A high-resolution crystal structure of the full-length protein has remained elusive, leaving questions regarding CFTR’s mechanism of action unanswered. Here, we explore these questions and we summarize our efforts at producing crystals of full-length CFTR using in meso and in surfo crystallization methods with a CFTR construct that is active and locked in an open conformation. We discuss small molecules known to rescue CFTR function and how they might aid high-resolution structure determination. From this work, we have gained insights regarding the direction of future crystallization trials.