Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. STKE, 14 September 2004
Vol. 2004, Issue 250, p. tw330
[DOI: 10.1126/stke.2502004tw330]

EDITORS' CHOICE

STRUCTURAL BIOLOGY Ensuring Adequate Gas Supplies

In an uncertain world, survival may depend on leaving nothing to chance. In biochemical terms, the way to place a spontaneously occurring process under control is to make an enzyme that catalyzes the reaction. Biological membranes are inherently permeable to gases, such as oxygen, yet Khademi et al. (see the cover and the Perspective by Knepper and Agre) now describe a bacterial protein that functions as an ammonia channel. The crystal structure of AmtB reveals a vestibule where the water-soluble species NH4+ is deprotonated and a hydrophobic conduit enables NH3 to cross the membrane. The human analog of AmtB is the well-known rhesus or Rh factor.

S. Khademi, J. O'Connell III, J. Remis, Y. Robles-Colmenares, L. J. W. Miercke, R. M. Stroud, Mechanism of ammonia transport by Amt/MEP/Rh: Structure of AmtB at 1.35 A. Science 305, 1587-1594 (2004). [Abstract] [Full Text]

M. A. Knepper, P. Agre, The atomic architecture of a gas channel. Science 305, 1573-1574 (2004). [Summary] [Full Text]

Citation: Ensuring Adequate Gas Supplies. Sci. STKE 2004, tw330 (2004).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882