Phosphocholine cytidylyltransferases catalyze the synthesis of CDP-choline.
This family contains proteins similar to prokaryotic phosphocholine (P-cho) cytidylyltransferases. Phosphocholine (PC) cytidylyltransferases catalyze the transfer of a cytidine monophosphate from CTP to phosphocholine to form CDP-choline. PC is the most abundant phospholipid in eukaryotic membranes and it is also important in prokaryotic membranes. For pathogenic prokaryotes, the cell surface PC facilitates the interaction with host surface and induces attachment and invasion. In addition cell wall PC serves as scaffold for a group of choline-binding proteins that are secreted from the cells. Phosphocholine (PC) cytidylyltransferase is a key enzyme in the prokaryotic choline metabolism pathway. It has been hypothesized to consist of a choline transport system, a choline kinase, CTP:phosphocholine cytidylyltransferase, and a choline phosphotransferase that transfers P-Cho from CDP-Cho to either lipoteichoic acid or lipopolysaccharide.