Evidence for crucial electrostatic interactions between Bcl-2 homology domains BH3 and BH4 in the anti-apoptotic Nr-13 protein.

Nr-13 is an anti-apoptotic member of the Bcl-2 family previously shown to interact with Bax. The biological significance of this interaction was explored both in yeast and vertebrate cells and revealed that Nr-13 is able to counteract the pro-apoptotic activity of Bax. The Bax-interacting domain has been identified and corresponds to alpha-helices 5 and 6 in Nr-13.