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The SecB chaperone is involved in the secretion of the Serratia marcescens HasA protein through an ABC transporter
Author(s) -
Delepelaire Philippe,
Wandersman Cécile
Publication year - 1998
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/17.4.936
Subject(s) - biology , serratia marcescens , chaperone (clinical) , secretion , transporter , atp binding cassette transporter , microbiology and biotechnology , escherichia coli proteins , transport protein , bacterial protein , biochemistry , escherichia coli , gene , medicine , pathology
The secretion pathways of the heme‐binding protein HasA from Serratia marcescens and of the metalloproteases A, B, C and G from Erwinia chrysanthemi have been reconstituted in Escherichia coli . They are secreted in a single step from the cytoplasm across both membranes of the Gram‐negative envelope, after recognition of their specific C‐terminal secretion signal by their cognate ABC transporter. We report strong evidence that both HasA and the metalloproteases bind the SecB chaperone involved in the export of several envelope proteins via the Sec pathway. We also show that the secretion of the HasA protein is strongly dependent upon SecB in the reconstituted system, whereas that of the proteases is not. HasA secretion in the original host is strongly inhibited by a protein known to interfere with E.coli SecB function. We propose that the proteins secreted by the ABC pathway may have to be unfolded for efficient secretion.