Helix-turn-Helix

Two helices are connected by a small loop or turn

These helices are stabilized by non-polar contacts between the helices

Mostly found in DNA binding proteins, directly involved in DNA binding

Generally consists of 20 amino acids

Second helix is involved in DNA binding, enters in major groove of the target site

TLS Online TPP Program

#Id: 8331

#Unit 2. Cellular Organization

Cytochalasin D, 

a fungal alkaloid, depolymerizes actin filaments by binding to the (+) end of F-actin.

TLS Online TPP Program

#Id: 8332

#Unit 2. Cellular Organization

Latrunculin, 

a toxin secreted by sponges, binds and sequesters G-actin

TLS Online TPP Program

#Id: 8333

#Unit 2. Cellular Organization

Jasplakinolide,

a sponge toxin, enhances nucleation by binding and stabilizing actin dimers and lowering the Cc.

TLS Online TPP Program

#Id: 8334

#Unit 2. Cellular Organization

Phalloidin 

isolated from Amanita phalloides, binds at the interface between subunits in F-actin, locking adjacent subunits together and preventing depolymerization.

TLS Online TPP Program

#Id: 8335

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8336

#Unit 2. Cellular Organization

Actin filament treadmilling is accelerated by:

Profilin and Cofilin