Bacterial membrane phosphatidylglycerol-rich domain (PG-rich domain)

Bacterial membrane phosphatidylglycerol-rich domains are specialized, non-randomly distributed regions within the bacterial cytoplasmic membrane characterized by high concentrations of the anionic phospholipid phosphatidylglycerol (PG) (Mileykovskaya & Dowhan, 2009, J Biol Chem). These domains serve as essential organizational hubs, facilitating the localization of key proteins involved in cell division, such as the Min system, and enzymes required for cell wall biosynthesis (Barák & Muchová, 2013, Int J Microbiol). Because PG is a primary component of bacterial membranes but is largely absent from the outer leaflet of mammalian plasma membranes, these domains represent a highly selective target for antimicrobial therapy. The lipopeptide antibiotic daptomycin specifically targets these domains in a calcium-dependent manner, where it inserts into the bilayer, oligomerizes, and causes rapid membrane depolarization and cell death (Taylor & Palmer, 2016, Front Org Synth Chem). Additionally, many cationic antimicrobial peptides (AMPs) exploit the negative charge density of these domains to achieve selective binding and membrane disruption. While highly effective against multidrug-resistant Gram-positive pathogens, drugs targeting these domains can be limited by host factors, such as the sequestration of daptomycin by pulmonary surfactant (Silverman et al., 2003, Antimicrob Agents Chemother).

Other names

Phosphatidylglycerol domainAnionic lipid domainPG domainBacterial anionic membrane domainBacterial membrane raft-like domain

Selective binding to anionic phosphatidylglycerol headgroups followed by calcium-dependent membrane insertion, oligomerization, and subsequent pore formation or depolarization (Taylor & Palmer, 2016).