Protein translocation by bacterial toxin channels: a comparison of diphtheria toxin and colicin Ia.
Regions of both colicin Ia and diphtheria toxin N-terminal to the channel-forming domains can be translocated across planar phospholipid bilayer membranes. In this article we show that the translocation pathway of diphtheria toxin allows much larger molecules to be translocated than does the translocation pathway of colicin Ia. In particular, the folded A chain of diphtheria toxin is readily translocated by that toxin but is not translocated by colicin Ia. This difference cannot be attributed to specific recognition of the A chain by diphtheria toxin's translocation pathway because the translocation pathway also accommodates folded myoglobin.
Wu
Zhengyan
Z
Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Jakes
Karen S
KS
Samelson-Jones
Ben S
BS
Lai
Bing
B
Zhao
Gang
G
London
Erwin
E
Finkelstein
Alan
A
D003087:Colicins / Q000737:chemistry*; D004167:Diphtheria Toxin / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D009211:Myoglobin / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D021381:Protein Transport
D003087:Colicins; D004167:Diphtheria Toxin; D008051:Lipid Bilayers; D009211:Myoglobin; D010743:Phospholipids