Whoop whoop: pertussis toxin

What does it look like?

Pertussis toxin from Bordetlla pertussis.

Pertussis toxin from Bordetlla pertussis.

What is it?

Pertussis toxin is released by virulent forms of the bacteria Bordetlla pertussis, the cause of whooping cough. Whooping cough gets its name from the characteristic ‘whooping’ sound that infected children make when coughing.

The pertussis toxin is known as an AB5 toxin as it contains an A subunit (in red), which is a catalytic subunit, and five B subunits (other colours) that transport the toxin into the cells of those infected with B. pertussis. This AB arrangement is similar to other crystal structures seen on this blog such as anthrax toxin and ricin.

The B subunits of the pertussis toxin bind to receptors on the cell membrane and the toxin is internalised into the cell. The A subunit has catalytic activity known as ADP-ribosylation, and once inside the cell, the A subunit is activated. The A subunit modifies a protein called G-protein by bonding a molecule of ADP-ribose onto the G protein. This prevents G-protein from interacting with G-protein coupled receptors, thus disputing the cells internal lines of communication.

Where does it come from?

The crystal structure of pertussis toxin was first solved by Penelope Stein and colleagues at the University of Alberta, Canada in 1994 [1]. The crystal structure is from the protein data bank, PDB code 1PRT.

[1] P.E. Stein, A. Boodhoo, G.D. Armstrong, S.A. Cockle, M.H. Klein, R.J. Read: The crystal structure of pertussis toxin. Structure (1994) 2: 45-57.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s