Protein Domain : Preprotein translocase SecG subunit IPR004692

Type	Family
Description	Secretion across the inner membrane in some Gram-negative bacteria occurs via the preprotein translocase pathway. Proteins are produced in the cytoplasm as precursors, and require a chaperone subunit to direct them tothe translocase component [ ]. From there, the mature proteins are either targeted to the outermembrane, or remain as periplasmic proteins. The translocase protein subunits are encoded on the bacterial chromosome.The translocase itself comprises 7 proteins, including a chaperone protein (SecB), an ATPase (SecA), an integral membrane complex (SecCY, SecE and SecG), and two additional membrane proteins that promote the release ofthe mature peptide into the periplasm (SecD and SecF) [ ]. The chaperone protein SecB [] is a highly acidic homotetrameric protein that exists as a "dimer of dimers"in the bacterial cytoplasm. SecB maintains preproteins in an unfolded state after translation, and targets these to the peripheral membraneprotein ATPase SecA for secretion [ ]. Together withSecY and SecG, SecE forms a multimeric channel through which preproteins are translocated, using both proton motive forces and ATP-driven secretion. The latter is mediated by SecA. SecG has two transmembrane domains, both of which contribute to the recognition of preprotein signalsequences by the translocation complex [ ]. The protein also undergoesmembrane topology inversion when coupled to the SecA cycle [ ].
Short Name	SecG