Premium
Determination of regions of Escherichia coli SecA responsible for SecYEG binding and membrane cycling: a genetic screen of suppressor mutants that suppress the secA100 translocation defect.
Author(s) -
Das Sanchaita
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb23-d
Subject(s) - mutant , suppressor , biology , chromosomal translocation , suppressor mutation , escherichia coli , genetics , mutation , genetic screen , microbiology and biotechnology , membrane protein , transport protein , gene , membrane
Determination of the regions of SecA responsible for SecYEG binding and membrane cycling is a critical and yet unresolved problem: there have been conflicting reports on this topic from both genetic and biochemical studies. In order to clarify this problem, we are pursuing a genetic strategy by isolation of suppressor mutants of a dominant negative secA100(Cs) mutant that synthesizes a nonfunctional and toxic SecA protein with normal SecYEG‐binding activity. Suppressor mutants that continue to overproduce the SecA100 protein have been isolated, and they have been classified genetically into intragenic and extragenic suppressors. Fractionation of the intragenic suppressor mutants suggests ones with defects in either SecA membrane binding or membrane insertion. Future work will be aimed at identifying whether these alterations in SecYEG binding or membrane insertion activity are due to direct or indirect effects, localization of SecYEG‐binding determinants on SecA structure, confirmation of our assignments, and characterization of the extragenic suppressor mutants utilizing additional genetic and biochemical approaches. Funding provided by National Institute of Health