Stoichiometry of SecYEG in the active translocase of Escherichia coli varies with precursor species.
Mao C, Cheadle CE, Hardy SJ, Lilly AA, Suo Y, Sanganna Gari RR, King GM, Randall LL. Proc Natl Acad Sci U S A. 2013 Jul 16; 110(29):11815-20. Epub 2013 Jul 1.