Phospho-Transferase System : (PTS)

Phospho-tranaferase System : (PTS)

Group Translocation :

In group translocation solute molecules are move across membrane without modification and taken by group translocation Phospho-transferase is the 

Best example of it in which Phospho-enol-pyruvate means phosphorylation of suger by Phospho-transferase System (PTS) 

as earlier mentioned above Various sugers goes under phosphorylating process bu utilizing the Phosphoenolpyruvate (PEP) as  phosphate donor whats why its known as Phospho-transerase System (PTS).

PEP+Suger(outside)----->Pyruvate+Suger-P (inside)

While in E.coli & Salmonella typhimurium consists two enzymes with low molecular weight heat stable protein called (HPr) & Enzyme Ist (EI) these are cytoplasmic.

While Enzyme IInd (EII) is more variable im structure & often composed of three domains/subunits.

domains/subunits of EII i.e. E (Second)

EII-A : is cytoplasmic & soluble

EII-B : is hydrophilic but attached to EII-C

EII-C : is hydrophobic protein embedded in membrane.

High energy phosphate is transferred from PEP to Enzyme II (EII) with aid of Enzyme I (EI) & HPr.

Suger molecule is phosphorylated as it carried out across membrane by Enzyme II (EII).

Enzyme II (EII) transports only specific sugers which varies with PTS where the Enzyme I (EI) & HPr are common to all PTS.

PTS are widely distributed in Prokaryotes and in Aerobic bacteria lack PTS genera Escherichia , Salmonella , Staphylococcus & othet facultative Anaerobic bacteria have  phosphotraaferase systems ;

Some obligate anaerobes (Clostridium) also have PTS's.

Many Carbohydrates transports by this system E.coli takes up Glucose , Fructose , Mannitol , Sucrose , N-acetylglucosamine & Cellobiose are comes under group translocation.