From: Genome-wide protein localization prediction strategies for gram negative bacteria
Export/Insertion System | Function | Core components | Domains | Localization1 | Comments |
---|---|---|---|---|---|
General (Sec) | Translocation of unfolded proteins across the inner membrane | SecY | TIGR00967 Pfam00344 | IM | Signal peptides cleaved by LspA tend to be shorter than those cleaved by LepB |
 |  | SecE | TIGR00964 Pfam00584 | IM |  |
 |  | SecG | TIGR00810 Pfam03840 | IM |  |
Twin arginine (Tat) | Translocation of folded proteins across the inner membrane | TatA | TIGR01411 Pfam02416 | IM | respiratory proteins that require cytoplasmic enzymes to covalently attachment metal cofactors (e.g. have iron sulfur, copper, molybdopterin) are expected substrates |
 |  | TatB | TIGR01410 Pfam02416 | IM |  |
 |  | TatC | TIGR00945 Pfam00902 | IM |  |
Holin | Translocation of phage endolysin across the inner membrane | Holin | Numerous, but Genus-specific | IM | Encoded near endolysin in double-strand phage |
Lol | Insertion of lipoproteins in the outer membrane | LolB | TIGR00548 Pfam03550 | LP-OM | beta and gamma Proteobacteria also have LolA having TIGR00547 and pfam03548 domains |
 |  | LolC | TIGR00548 Pfam03550 | IM |  |
 |  | LolD | TIGR00221 | Cyt-IM assoc |  |
 |  | LolE | TIGR02212 | IM |  |
Bam | Insertion of beta barrel proteins in the outer membrane | BamA | TIGR03303 | OM | With the exception of proteins having large periplasmic domains, expect a genus-specific C-terminal sorting motif |
 |  | BamB | TIGR03300 | LP-OM |  |
 |  | BamC | TIGR03302 | LP-OM |  |
 |  | BamD | pfam06804 | LP-OM |  |
 |  | BamE | Pfam04355 | LP-OM |  |