CymA of Klebsiella oxytoca outer membrane: binding of cyclodextrins and study of the current noise of the open channel.

CymA, the outer membrane component of the cyclodextrin (CD) uptake and metabolism system of Klebsiella oxytoca, was reconstituted into lipid bilayer membranes. The channel properties of this unusual porin were studied in detail. The binding of CDs to the channel resulted in its complete block for ion transport.