Snap shots of cations' transport.

I came to Jack Kaplan’s group at the University of Pennsylvania in Feb 1985. Jack was the one who really invented caged compounds, so he could study the Na pump (his first love). 1985 was a momentous year (not because I went to Jack’s lab), as the structure of the Ca pump was published my David MacLennan that summer. I vividly recall Jack and Carlos Pedemonte pouring over the details of the primary structure for hours. I was an organic chemist, therefore it was very strange to go into a world where even the linear sequence of atoms of a molecule that was being studied was not known! I remember saying to anyone who would listen, "How can you study a molecule when you do not know its structure?"

I meant, of course, a 3-dimensional structure, as that’s how chemists had thought for many years. Well it has been a long time coming, but finally three papers have been published in Nature which bring "chemical resolution" to these biological transport molecules. Poul Nissen and co-workers published 5 new atomic resolution X-ray pictures of the 3 major members of the P-type ATPase family: the Ca, Na/K and Proton ATPases. The Ca pump has been the subject of several such studies already, but this pump is now joined by its two closest relatives.

Let us all congratulate Poul and colleagues in this fabulous contribution to science.

Nature (2007) 450:1036-1042; 1043-49; 1111-1114.

For a review of the previous crystal structures of the Ca pump see Journal of Bioenergetics and Biomembranes (2005) 37:359-364. Here the structures of Toyoshima and co-workers are also discussed.