Clostridial hydrophobic W
A novel extracellular macromolecular system has been proposed based on the proteins containing ChW repeats. ChW stands for Clostridial hydrophobic with conserved W (tryptophan). This repeat was originally described in Clostridium acetobutylicum but is also found in other Gram-positive bacteria including Enterococcus faecalis, Streptococcus agalactiae and Streptomyces coelicolor.