Practical GK-12

Membrane proteins

Aims

• To reinforce knowledge about the structure of helical membrane proteins.

Objectives

After this practical you will:

• be aware of the structures of some transmembrane proteins.

Exercises

1. Protein Data Bank entry 1H68 contains the structure of Sensory Rhodopsin II from Natronomonas pharaonis. Look at the distribution of hydrophobic and hydrophilic residues in this structure.

2. Protein Data Bank entry 1ZLL contains an ensemble of 20 NMR-derived structure of human phospholamban.

   Simmerman et al. (1996) identified residues whose mutation to Ala or Phe affected Phospholamban's ability to form a pentamer. Locate these residues on the three-dimensional structure of phospholamban (e.g. colour these residues using a molecular graphcs program).

   • Simmerman HK, Kobayashi YM, Autry JM, Jones LR. A leucine zipper stabilizes the pentameric membrane domain of phospholamban and forms a coiled-coil pore structure. J Biol Chem. 1996 Mar 8;271(10):5941-6. (PubMed)