Escherichia coli K-12 substr. MG1655 Polypeptide: TatC

Gene: tatC Accession Numbers: EG11479 (EcoCyc), b3839, ECK3832

Synonyms: mttB, yigU, yigV

Regulation Summary Diagram: ?

Regulation summary diagram for tatC

Component of: TatABCE protein export complex (extended summary available)

TatC is a subunit of the TatABCE (twin-arginine translocation) complex for the export of folded proteins across the cytoplasmic membrane. Although its exact function is not known, it has been shown through deletion mutation studies [Bogsch98] to be essential for Tat-dependent protein export. Membrane topology predictions using experimentally determined C terminus locations indicate that TatC has 6 transmembrane helices and the C-terminus is located in the periplasm [Rapp04],[Drew02]. TatC may form functional dimers [Maldonado11].

tatC is one of a network of genes believed to play a role in promoting the stress-induced mutagenesis (SIM) response of E. coli K-12 [Al12].

Citations: [Bolhuis01]

Gene Citations: [Huerta03, Wexler00, Weiner98, Sargent98a, Lindenstrauss06]

Locations: inner membrane

Map Position: [4,020,759 -> 4,021,535] (86.66 centisomes, 312°)
Length: 777 bp / 258 aa

Molecular Weight of Polypeptide: 28.876 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0012547 , DIP:DIP-58537N , EchoBASE:EB1445 , EcoGene:EG11479 , EcoliWiki:b3839 , Mint:MINT-8083961 , OU-Microarray:b3839 , PortEco:tatC , PR:PRO_000024030 , Protein Model Portal:P69423 , RefSeq:NP_418282 , RegulonDB:EG11479 , SMR:P69423 , String:511145.b3839 , UniProt:P69423

Relationship Links: InterPro:IN-FAMILY:IPR002033 , InterPro:IN-FAMILY:IPR019820 , Panther:IN-FAMILY:PTHR30371:SF0 , Pfam:IN-FAMILY:PF00902 , Prints:IN-FAMILY:PR01840 , Prosite:IN-FAMILY:PS01218

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0065002 - intracellular protein transmembrane transport Inferred from experiment [Weiner98, Bolhuis01]
GO:0006810 - transport Inferred by computational analysis [UniProtGOA11a]
GO:0015031 - protein transport Inferred by computational analysis [UniProtGOA11a]
GO:0043953 - protein transport by the Tat complex Inferred by computational analysis [GOA06]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Maldonado11a, Kostecki10]
GO:0008565 - protein transporter activity Inferred from experiment [Bogsch98]
GO:0009977 - proton motive force dependent protein transmembrane transporter activity Inferred from experiment [Yahr01]
GO:0008320 - protein transmembrane transporter activity Inferred by computational analysis [GOA06]
Cellular Component: GO:0005622 - intracellular Inferred from experiment [Weiner98, Bolhuis01]
GO:0005886 - plasma membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, DiazMejia09, Zhang07a, Daley05]
GO:0016020 - membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11a, Wexler00]
GO:0033281 - TAT protein transport complex Inferred from experiment Inferred by computational analysis [GOA06, Bolhuis01]
GO:0005887 - integral component of plasma membrane Inferred by computational analysis [GOA06]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11a, GOA01a]

MultiFun Terms: cell structure membrane
transport Electrochemical potential driven transporters Porters (Uni-, Sym- and Antiporters)

Essentiality data for tatC knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enriched Yes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]

Subunit of: TatABCE protein export complex

Subunit composition of TatABCE protein export complex = [TatB][TatC][TatE][TatA]

The twin-arginine translocation (Tat) system works in parallel with the E. coli Sec translocation system to transport folded proteins across the cytoplasmic membrane [Weiner98]. While the Sec system transports unfolded proteins, Tat translocase functions to move structured macromolecular substrates, usually containing cofactors, across the cytoplasmic membrane. These proteins include those critical for bacterial respiratory and photosynthetic energy metabolism. Substrates utilizing the Tat pathway are characterized by essentially invariant amino-terminal sequences which contain consecutive arginine residues.

Cofactor-containing Tat substrates acquire their cofactors in the cytoplasm where they attain a folded conformation [Berks00]. In studies using mutated tat strains [Sargent98a], precursor proteins that accumulate in the cytoplasm contain cofactors. In even more direct studies using folded green fluorescent protein (GFP) fused with the Tat signal peptide [Santini01], the GFP was found to localize to the periplasm.

The Tat apparatus in E. coli is encoded by genes located in two genetic loci. The tatA operon encodes tatABCD; tatE is coded for in a separate locus [Bogsch98]. TatA, TatB and TatE are similar in structure, predicted to comprise a membrane-spanning alpha helix at the amino terminus, followed by an amphipathic helix at the cytoplasmic side of the membrane and a variable-length carboxy terminus. TatA has been shown to be a fully integral membrane protein [De01]. TatA and TatE share 50% sequence identity and share overlapping functions in Tat translocation. Deletion of either of these genes results in a decrease in the range of substrates, while deletions in both results in complete loss of Tat-dependent export [Sargent98a]. Although TatB has 20% sequence identity with TatA/TatE, it serves a distinct function in export. A deletion mutation of tatB alone is enough to completely abolish the translocation of some but not all endogenous Tat substrates [Ize02]. TatC has similarly been shown to be essential for Tat-dependent protein export [Bogsch98]. tatD encodes a soluble cytoplasmic protein with nuclease activity [Wexler00]. Deletion studies of tatD and two of its homologues indicate that TatD family proteins are not essential for Tat-dependent protein translocation.

Functionally, protein translocation in the Tat system is energized exclusively by a transmembrane proton electrochemical gradient with no involvement of nucleotide hydrolysis [Mould91] unlike the Sec translocation system which is powered by ATP hydrolysis.

Localization studies using fusion proteins with green fluorescent protein (GFP) demonstrated that TatA, TatB and TatC proteins all localize to the cellular poles, suggesting that active translocon poles are primarily located at polar positions in E. coli [Berthelmann04].

Within the purified Tat complex, TatB and TatC are present in a strict 1:1 ration and a TatBC fusion protein supports Tat dependent transport [Bolhuis01]. Three-dimensional structures of TatBC-substrate complexes and unliganded TatBC have been obtained by single particle electron microscopy. The structures show substrate binding on the periphery of the TatBC complex and suggest that TatBC undergoes structural reorganisation upon substrate binding [Tarry09].

An experimental approach using alkaline phosphatase (PhoA) fusions to protein signal sequences has allowed discrimination between the major modes of transport, including the Tat protein export system, across the inner membrane [Marrichi08].

Review: [Muller05]

Locations: inner membrane

GO Terms:

Biological Process: GO:0065002 - intracellular protein transmembrane transport Inferred from experiment [Weiner98, Bolhuis01]
Molecular Function: GO:0009977 - proton motive force dependent protein transmembrane transporter activity Inferred from experiment [Yahr01]
Cellular Component: GO:0033281 - TAT protein transport complex Inferred from experiment [Bolhuis01]

Revised 26-Nov-2008 by Nolan L , Macquarie University

Enzymatic reaction of: TatABCE protein export complex

Transport reaction diagram for TatABCE protein export complex

Sequence Features

Protein sequence of TatC with features indicated

Feature Class Location Citations Comment
Cleavage-of-Initial-Methionine 1
[Bolhuis01, UniProt11]
UniProt: Removed.
Chain 2 -> 258
UniProt: Sec-independent protein translocase protein tatC;
Mutagenesis-Variant 17
[Allen02, UniProt11]
UniProt: No anaerobic growth and no torA export.
Mutagenesis-Variant 20
[Allen02, UniProt11]
[Allen02, UniProt11]
L → A: 25% decrease in anaerobic growth and 75% decrease in torA export.
LLN → missing: No anaerobic growth and 75% decrease in torA export.
Transmembrane-Region 24 -> 44
UniProt: Helical; Non-Experimental Qualifier: potential.
Transmembrane-Region 76 -> 96
UniProt: Helical; Non-Experimental Qualifier: potential.
Mutagenesis-Variant 94
[Buchanan02, UniProt11]
F → A or L: Loss of function.
Mutagenesis-Variant 103
[UniProt11, Buchanan02, UniProt11]
[Buchanan02, UniProt11]
E → A, D or R: Loss of function.
E → Q: Severely retard but does not abolish activity.
Transmembrane-Region 116 -> 136
UniProt: Helical; Non-Experimental Qualifier: potential.
Transmembrane-Region 157 -> 177
UniProt: Helical; Non-Experimental Qualifier: potential.
Transmembrane-Region 193 -> 210
UniProt: Helical;; Non-Experimental Qualifier: potential;
Mutagenesis-Variant 211
[Buchanan02, UniProt11]
[Buchanan02, UniProt11]
D → E or N: Decrease in torA export activity.
D → A: Export activity of torA blocked. Export of torA restored; when associated with A-94 or A-103.
Transmembrane-Region 212 -> 232
UniProt: Helical; Non-Experimental Qualifier: potential.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b3839 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11479; confirmed by SwissProt match.


Al12: Al Mamun AA, Lombardo MJ, Shee C, Lisewski AM, Gonzalez C, Lin D, Nehring RB, Saint-Ruf C, Gibson JL, Frisch RL, Lichtarge O, Hastings PJ, Rosenberg SM (2012). "Identity and function of a large gene network underlying mutagenic repair of DNA breaks." Science 338(6112);1344-8. PMID: 23224554

Allen02: Allen SC, Barrett CM, Ray N, Robinson C (2002). "Essential cytoplasmic domains in the Escherichia coli TatC protein." J Biol Chem 277(12);10362-6. PMID: 11781311

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Berks00: Berks BC, Sargent F, De Leeuw E, Hinsley AP, Stanley NR, Jack RL, Buchanan G, Palmer T (2000). "A novel protein transport system involved in the biogenesis of bacterial electron transfer chains." Biochim Biophys Acta 1459(2-3);325-30. PMID: 11004447

Berthelmann04: Berthelmann F, Bruser T (2004). "Localization of the Tat translocon components in Escherichia coli." FEBS Lett 569(1-3);82-8. PMID: 15225613

Bogsch98: Bogsch EG, Sargent F, Stanley NR, Berks BC, Robinson C, Palmer T (1998). "An essential component of a novel bacterial protein export system with homologues in plastids and mitochondria." J Biol Chem 273(29);18003-6. PMID: 9660752

Bolhuis01: Bolhuis A, Mathers JE, Thomas JD, Barrett CM, Robinson C (2001). "TatB and TatC form a functional and structural unit of the twin-arginine translocase from Escherichia coli." J Biol Chem 276(23);20213-9. PMID: 11279240

Buchanan02: Buchanan G, de Leeuw E, Stanley NR, Wexler M, Berks BC, Sargent F, Palmer T (2002). "Functional complexity of the twin-arginine translocase TatC component revealed by site-directed mutagenesis." Mol Microbiol 43(6);1457-70. PMID: 11952898

Daley05: Daley DO, Rapp M, Granseth E, Melen K, Drew D, von Heijne G (2005). "Global topology analysis of the Escherichia coli inner membrane proteome." Science 308(5726);1321-3. PMID: 15919996

De01: De Leeuw E, Porcelli I, Sargent F, Palmer T, Berks BC (2001). "Membrane interactions and self-association of the TatA and TatB components of the twin-arginine translocation pathway." FEBS Lett 506(2);143-8. PMID: 11591389

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Drew02: Drew D, Sjostrand D, Nilsson J, Urbig T, Chin CN, de Gier JW, von Heijne G (2002). "Rapid topology mapping of Escherichia coli inner-membrane proteins by prediction and PhoA/GFP fusion analysis." Proc Natl Acad Sci U S A 99(5);2690-5. PMID: 11867724

Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Huerta03: Huerta AM, Collado-Vides J (2003). "Sigma70 promoters in Escherichia coli: specific transcription in dense regions of overlapping promoter-like signals." J Mol Biol 333(2);261-78. PMID: 14529615

Ize02: Ize B, Gerard F, Zhang M, Chanal A, Voulhoux R, Palmer T, Filloux A, Wu LF (2002). "In vivo dissection of the Tat translocation pathway in Escherichia coli." J Mol Biol 317(3);327-35. PMID: 11922668

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Kostecki10: Kostecki JS, Li H, Turner RJ, DeLisa MP (2010). "Visualizing interactions along the Escherichia coli twin-arginine translocation pathway using protein fragment complementation." PLoS One 5(2);e9225. PMID: 20169075

Lindenstrauss06: Lindenstrauss U, Bruser T (2006). "Conservation and variation between Rhodobacter capsulatus and Escherichia coli Tat systems." J Bacteriol 188(22);7807-14. PMID: 16980457

Maldonado11: Maldonado B, Buchanan G, Muller M, Berks BC, Palmer T (2011). "Genetic Evidence for a TatC Dimer at the Core of the Escherichia coli Twin Arginine (Tat) Protein Translocase." J Mol Microbiol Biotechnol 20(3);168-75. PMID: 21709427

Maldonado11a: Maldonado B, Kneuper H, Buchanan G, Hatzixanthis K, Sargent F, Berks BC, Palmer T (2011). "Characterisation of the membrane-extrinsic domain of the TatB component of the twin arginine protein translocase." FEBS Lett 585(3);478-84. PMID: 21237157

Marrichi08: Marrichi MJ, Camacho L, Russell DG, Delisa MP (2008). "Genetic toggling of alkaline phosphatase folding reveals signal peptides for all major modes of transport across the inner membrane of bacteria." J Biol Chem 283(50):35223-35. PMID: 18819916

Mould91: Mould RM, Robinson C (1991). "A proton gradient is required for the transport of two lumenal oxygen-evolving proteins across the thylakoid membrane." J Biol Chem 266(19);12189-93. PMID: 1648086

Muller05: Muller M, Klosgen RB (2005). "The Tat pathway in bacteria and chloroplasts (review)." Mol Membr Biol 22(1-2);113-21. PMID: 16092529

Rapp04: Rapp M, Drew D, Daley DO, Nilsson J, Carvalho T, Melen K, De Gier JW, Von Heijne G (2004). "Experimentally based topology models for E. coli inner membrane proteins." Protein Sci 13(4);937-45. PMID: 15044727

Santini01: Santini CL, Bernadac A, Zhang M, Chanal A, Ize B, Blanco C, Wu LF (2001). "Translocation of jellyfish green fluorescent protein via the Tat system of Escherichia coli and change of its periplasmic localization in response to osmotic up-shock." J Biol Chem 276(11);8159-64. PMID: 11099493

Sargent01: Sargent F, Gohlke U, De Leeuw E, Stanley NR, Palmer T, Saibil HR, Berks BC (2001). "Purified components of the Escherichia coli Tat protein transport system form a double-layered ring structure." Eur J Biochem 268(12);3361-7. PMID: 11422364

Sargent98a: Sargent F, Bogsch EG, Stanley NR, Wexler M, Robinson C, Berks BC, Palmer T (1998). "Overlapping functions of components of a bacterial Sec-independent protein export pathway." EMBO J 17(13);3640-50. PMID: 9649434

Tarry09: Tarry MJ, Schafer E, Chen S, Buchanan G, Greene NP, Lea SM, Palmer T, Saibil HR, Berks BC (2009). "Structural analysis of substrate binding by the TatBC component of the twin-arginine protein transport system." Proc Natl Acad Sci U S A 106(32);13284-9. PMID: 19666509

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProt11a: UniProt Consortium (2011). "UniProt version 2011-11 released on 2011-11-22 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Weiner98: Weiner JH, Bilous PT, Shaw GM, Lubitz SP, Frost L, Thomas GH, Cole JA, Turner RJ (1998). "A novel and ubiquitous system for membrane targeting and secretion of cofactor-containing proteins." Cell 93(1);93-101. PMID: 9546395

Wexler00: Wexler M, Sargent F, Jack RL, Stanley NR, Bogsch EG, Robinson C, Berks BC, Palmer T (2000). "TatD is a cytoplasmic protein with DNase activity. No requirement for TatD family proteins in sec-independent protein export." J Biol Chem 2000;275(22);16717-22. PMID: 10747959

Yahr01: Yahr TL, Wickner WT (2001). "Functional reconstitution of bacterial Tat translocation in vitro." EMBO J 20(10);2472-9. PMID: 11350936

Zhang07a: Zhang N, Chen R, Young N, Wishart D, Winter P, Weiner JH, Li L (2007). "Comparison of SDS- and methanol-assisted protein solubilization and digestion methods for Escherichia coli membrane proteome analysis by 2-D LC-MS/MS." Proteomics 7(4);484-93. PMID: 17309111

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Tue Oct 13, 2015, biocyc13.