- PMID:
10399921 , Related PDB id: UNKNOWN
- Authors:
- Gulbis JM, Mann S, MacKinnon R
- Title:
- Structure of a voltage-dependent K+ channel beta subunit.
- Journal:
- Cell. 1999 Jun 25;97(7):943-52.
- Abstract:
- The integral membrane subunits of many voltage-dependent potassium channels are associated with an additional protein known as the beta subunit. One function of beta subunits is to modify K+ channel gating. We have determined the structure of the conserved core of mammalian beta subunits by X-ray crystallography at 2.8 A resolution. Like the integral membrane component of K+ channels, beta subunits form a four-fold symmetric structure. Each subunit is an oxidoreductase enzyme complete with a nicotinamide co-factor in its active site. Several structural features of the enzyme active site, including its location with respect to the four-fold axis, imply that it may interact directly or indirectly with the K+ channel's voltage sensor. This structure suggests a mechanism for coupling membrane electrical excitability directly to chemistry of the cell.