7xhb
From Proteopedia
Structure of the SecA/SecYE/proOmpA(4Y)-sfGFP complex with ADP
Structural highlights
FunctionSECA_BACSU Part of the Sec protein translocase complex. Interacts with the SecYEG preprotein conducting channel. Has a central role in coupling the hydrolysis of ATP to the transfer of proteins into and across the cell membrane, serving as an ATP-driven molecular motor driving the stepwise translocation of polypeptide chains across the membrane (By similarity).[HAMAP-Rule:MF_01382] Publication Abstract from PubMedSecretory proteins are cotranslationally or posttranslationally translocated across lipid membranes via a protein-conducting channel named SecY in prokaryotes and Sec61 in eukaryotes. The vast majority of secretory proteins in bacteria are driven through the channel posttranslationally by SecA, a highly conserved ATPase. How a polypeptide chain is moved by SecA through the SecY channel is poorly understood. Here, we report electron cryomicroscopy structures of the active SecA-SecY translocon with a polypeptide substrate. The substrate is captured in different translocation states when clamped by SecA with different nucleotides. Upon binding of an ATP analog, SecA undergoes global conformational changes to push the polypeptide substrate toward the channel in a way similar to how the RecA-like helicases translocate their nucleic acid substrates. The movements of the polypeptide substrates in the SecA-SecY translocon share a similar structural basis to those in the ribosome-SecY complex during cotranslational translocation. Structural basis of SecA-mediated protein translocation.,Dong L, Yang S, Chen J, Wu X, Sun D, Song C, Li L Proc Natl Acad Sci U S A. 2023 Jan 10;120(2):e2208070120. doi: , 10.1073/pnas.2208070120. Epub 2023 Jan 4. PMID:36598944[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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