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The high affinity ATP binding site modulates the SecA–precursor interaction
Author(s) -
van Voorst Frank,
Vereyken Ingrid J,
de Kruijff Ben
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)02209-2
Subject(s) - atp hydrolysis , binding site , biochemistry , biophysics , chemiosmosis , chemistry , escherichia coli , plasma protein binding , phosphatidylglycerol , chaperone (clinical) , microbiology and biotechnology , biology , membrane , enzyme , atpase , phospholipid , atp synthase , phosphatidylcholine , gene , medicine , pathology
SecA is the central component of the protein‐translocation machinery of Escherichia coli . It is able to interact with the precursor protein, the chaperone SecB, the integral membrane protein complex SecYEG, acidic phospholipids and its own mRNA. We studied the interaction between prePhoE and SecA by using a site‐specific photocrosslinking strategy. We found that SecA is able to interact with both the signal sequence and the mature domain of prePhoE. Furthermore, this interaction was dependent on the type of nucleotide bound. SecA in the ADP‐bound conformation was unable to crosslink with the precursor, whereas the ATP‐bound conformation was active in precursor crosslinking. The SecA–precursor interaction was maintained in the presence of E. coli phospholipids but was loosened by the presence of phosphatidylglycerol bilayers. Examining SecA ATP binding site mutants demonstrated that ATP hydrolysis at the N‐terminal high affinity binding site is responsible for the changed interaction with the preprotein.