The topic of the May Biochem CUME exam (10/15/01) is

The structure and function of ABC transporters

It will focus on this recent paper from last month's issue of Science (September 7, 2001):

Chang and Roth, "Structure of MsbA from E. coli: A homolog of the Multi-drug Resistance ATP binding cassette transporters", Science 293:1793

This is an important paper. It describes the structure of an example of a general class of membrane proteins that can transport a variety of molecules across biological membranes as well as flip the orientation of phospholipids ("flippases"). The structure of the protein goes a long way to showing how both these functions could be carried out. The rise of multi-drug resistant pathogenic bacteria is becoming increasingly worrisome. Knowing how these proteins work may be the first step in understanding how to solve the problem.

You will be expected to have a general knowledge of these topics. This will require reading this paper and enough references until you have a good foundation. Click for PDF version of the paper

You are also advised to examine the structure of the protein. (Click for the PDB file of the coordinates) Note that this structure has several dimers in the unit cell. The best way to view is to restrict to one dimer (e.g. "restrict *A, *B").

 

-Kevin Redding