Table 1.

Insertion factor dependency for membrane proteins determined in the in vitro reconstitution system.

ProteinSecYEGMPIaseYidCProton motive forceReferences
MtlAEssentialEssentialConditionalNo effect6 and 7
Pf3 coatNot essentialEssentialStimulateStimulate7 and 22
3L-Pf3 coatNot essentialEssentialConditionalNo effect7, 15, 16, and 22
M13 procoatNot essentialEssentialStimulateStimulate6, 7, and 14
F0cNot essentialEssentialStimulateNo effect8, 9, and 23
Pf3-LepNot essential(This study)Not requiredNo effect24
Pf3-Lep V15DNot essential(This study)StimulateStimulate24
  • The insertion factor dependencies for specified membrane proteins are indicated. “Conditional” denotes that YidC stimulates insertion when the substrate level is high. In the case of Pf3-Lep and Pf3-Lep V15D, used in this study, the in vivo results are indicated.