YajC is a small single-pass inner-membrane protein encoded upstream of secD and
secF. It is identified in SecDF-YajC and SecYEG-SecDF-YajC-YidC assemblies
PMID:24550475, but
its individual mechanistic role has not been resolved; direct E. coli genetics
reported that "yajC is neither essential nor a sec gene" PMID:7507921.
No independent molecular function should be assigned to YajC from the available
evidence. The direct Sec-complex process annotation is acceptable for the
purified active holo-translocon, but the core statement should stay at complex
membership and inner-membrane localization.
The AcrB co-crystal structure assigned a single transmembrane density as YajC
but could not prove that the AcrB-YajC contact was physiologically responsible
for the weak drug-susceptibility phenotype PMID:18073115. The generic protein-binding row should therefore be removed as an
uninformative and biologically unsettled interaction record.
The generic YajC membrane row should be narrowed to plasma membrane based on
direct YajC topology and holo-translocon evidence.