Table 7.

Components of Sec-dependent protein export machineries ofB. subtilis, E. coli, M. jannaschii, and the ER of S. cerevisiaea

ComponentB. subtilisE. coliM. jannaschiiS. cerevisiae
Secretion-dedicated chaperonesFfh, FtsY, scRNAFfh, FtsY, 4.5S RNASrp54/19, FtsY, 7S RNASRP complex,b DPα/β
SecB
CsaA (?)YgjH (?)
General chaperonesGroEL, GroESGroEL, GroES
DnaK, DnaJ, GrpEDnaK, DnaJ, GrpEHsp70, Ydj1
Trigger factorTrigger factor
Translocation motorSecASecA
Ribosome
Kar2 (Bipc)
Translocation channelSecYSecYSecYSec61, Ssh1 (Sec61αc)
SecGSecGSec61βSbh1, Sbh2 (Sec61βc)
SecESecESecESss1 (Sec61γc)
SecDF, YrbFSecD/F, YajCSecD/F
Sec62/63
Sec66/67
SPasesSipS/T/U/V/PLepB
SipWSec11Sec11
LspALspA
SPPasesSppASppASppA
TepA
OpdA
Foldases (trans-acting)PrsASurA, PpiD, RotA, FkpACPR2, CPR4, CPR5, CPR8, FPR2
BdbA/B/CDsbA/B/C/D/E/GPDI, Ero1, Eug1
Kar2 (BiPc), Lhs1 (Hsp70c)
  • a Proteins with similar functions are placed in the same horizontal row.

  • b The SRP complex consists of scR1 RNA, Srp72p, Srp68p, Srp54p, Sec65p, Srp21p, Srp14p, and Srp7p (338).

  • c Synonymous names for mammalian homologues.