Periplasmic binding domain of ATP-binding cassette transporter-like systems that belong to the type I periplasmic binding fold protein superfamily
Periplasmic binding domain of ATP-binding cassette transporter-like systems that belong to the type I periplasmic binding fold protein superfamily. They are mostly present in archaea and eubacteria, and are primarily involved in scavenging solutes from the environment. ABC-type transporters couple ATP hydrolysis with the uptake and efflux of a wide range of substrates across bacterial membranes, including amino acids, peptides, lipids and sterols, and various drugs. These systems are comprised of transmembrane domains, nucleotide binding domains, and in most bacterial uptake systems, periplasmic binding proteins (PBPs) which transfer the ligand to the extracellular gate of the transmembrane domains. These PBPs bind their substrates selectively and with high affinity. Members of this group include ABC-type Leucine-Isoleucine-Valine-Binding Proteins (LIVBP), which are homologous to the aliphatic amidase transcriptional repressor, AmiC, of Pseudomonas aeruginosa. The uncharacterized periplasmic components of various ABC-type transport systems are included in this group.