Breakthrough: Structure of Membrane NhaA Protein

Filed in archive Drugs, Vaccines and Therapeutics on August 16, 2005

Image: Hebrew Uni Jerusalem

The structure of the membrane protein NhaA has been elucidated using x-ray diffraction techniques on three-dimensional crystals of the protein. The findings are published in a recent issue of Nature.

Because cells are virtually impervious to substances outside its cell membrane, membrane proteins such as NhaA serves as the channels through which substances get in and out of the cell. Membrane protein research is therefore instrumental in developing drugs and on genetic engineering of plants, for example. It is estimated that more than 60% of medicines are targeted at the cell membrane proteins.

Prof. Etana Padan of The Hebrew University of Jerusalem, who lead the research said,

"In the center of the protein we found a wide funnel which extends into the cell. The funnel narrows and ends at the point at which it binds with the sodium or the hydrogen deep within the cell membrane. Near that point two chains of the protein unite into a unique structure."

The researchers believe that this unique structure is the basis for the activity of the protein. The protein operates as a kind of pump,with the protein structure acting as a kind of molecular motor. This "motor" is connected to the area found at the mouth of the funnel that apparently conveys signals to "modulate" the motor according to the acidity within the cell.

Read the abstract of the Nature article here (full text available to subscribers).