PgpC

PgpC, or phosphatidylglycerophosphate phosphatase C, is a bacterial enzyme that catalyzes the dephosphorylation of phosphatidylglycerophosphate (PGP) to yield phosphatidylglycerol (PG) during the biosynthesis of phospholipids. It is part of a small family of PGP phosphatases that also includes PgpA and PgpB, providing overlapping activity in many organisms.

The pgpC gene encodes this enzyme in several bacterial species, including Escherichia coli, and orthologs are found across diverse Gram-negative bacteria and some Gram-positive species. PgpC is an integral membrane protein, predicted to contain multiple transmembrane helices with active-site regions located in peripheral loops near the membrane. Its activity is thought to occur in the inner membrane and may function with other PGP phosphatases to maintain cellular levels of phosphatidylglycerol.

Biochemically, PgpC hydrolyzes the phosphate group of PGP, generating PG and inorganic phosphate. The enzyme typically requires divalent metal ions for catalysis, and its operation contributes to the regulation of membrane lipid composition and homeostasis. Functional studies show that deleting pgpC can alter membrane phospholipid balance, with effects that can depend on the presence of PgpA and PgpB, indicating some redundancy.

Despite its conserved role, high-resolution structural data for PgpC are limited, and topology models are based on sequence analysis and related enzymes. Because phospholipid biosynthesis is essential, PgpC and related enzymes are of interest as potential targets for antimicrobial strategies.