Escherichia coli K-12 substr. MG1655 Polypeptide: putative protein secretion protein for export

Gene: gspK Accession Numbers: G7710 (EcoCyc), b3332, ECK3319

Synonyms: yheJ

Regulation Summary Diagram: ?

Regulation summary diagram for gspK

Component of: GspC-O secreton complex (extended summary available)

In Escherichia coli, gspK is a member of an operon of genes (gspC-O) which are not normally expressed [Francetic00] but are homologous to those encoding the secreton, or type II secretion machinery in Klebsiella oxytoca and Aeromonase hydrophila, among others [Francetic96]. The GspG, H, I, J and K proteins are similar to type IV pilus subunits [Nunn93], [Bleves98] and are referred to as pseudopilins [Okabe00]. Deletion mutation studies showed that the pseudopilins (with the exception of GspH) are required for protein secretion [Possot00].

Locations: inner membrane

Map Position: [3,460,946 -> 3,461,929] (74.59 centisomes, 269°)
Length: 984 bp / 327 aa

Molecular Weight of Polypeptide: 37.647 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0010894 , EchoBASE:EB2731 , EcoGene:EG12894 , EcoliWiki:b3332 , OU-Microarray:b3332 , PortEco:gspK , Pride:P45762 , Protein Model Portal:P45762 , RefSeq:NP_417791 , RegulonDB:G7710 , SMR:P45762 , String:511145.b3332 , UniProt:P45762

Relationship Links: InterPro:IN-FAMILY:IPR005628 , Pfam:IN-FAMILY:PF03934

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for gspK

GO Terms:

Biological Process: GO:0006810 - transport Inferred by computational analysis [UniProtGOA11a]
GO:0009306 - protein secretion Inferred by computational analysis [GOA01a]
GO:0015031 - protein transport Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005886 - plasma membrane Inferred by computational analysis [UniProtGOA11, UniProtGOA11a]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11a]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11a, GOA01a]

MultiFun Terms: All-Genes Pseudo-Genes Cryptic-Genes
MultiFun transport Putative uncharacterized transport protein

Essentiality data for gspK 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: GspC-O secreton complex

Subunit composition of GspC-O secreton complex = [GspC][GspD][GspE][GspF][GspG][GspH][GspI][GspJ][GspK][GspL][GspM][GspO]
         putative protein secretion protein for export = GspC (summary available)
         putative protein secretion protein for export = GspD (summary available)
         putative protein secretion protein for export = GspE (extended summary available)
         putative protein secretion protein for export = GspF (summary available)
         putative protein secretion protein for export = GspG (summary available)
         putative protein secretion protein for export = GspH (summary available)
         putative protein secretion protein for export = GspI (summary available)
         putative protein secretion protein for export = GspJ (summary available)
         putative protein secretion protein for export = GspK (summary available)
         putative protein secretion protein for export = GspL (summary available)
         putative protein secretion protein = GspM (summary available)
         leader peptidase, integral membrane protein = GspO (extended summary available)

GspC-O, the type II secretion or secreton complex in Escherichia coli has also been known as the general secretory pathway (GSP) for the export of proteins across the outer membranes of gram-negative bacteria [Pugsley93]. Translocation across the cytoplasmic membrane prior to secreton-dependent secretion can take place via the signal peptide-dependent Sec pathway or the twin-arginine translocation (TAT) system [Voulhoux01]. After transport across the outer membrane, the translocated proteins may be either released into the medium or stay attached to the outer membrane and assembled into surface organelles [Pugsley93, Pugsley98]. The secreton facilitates the extrusion of folded proteins through a putative large gated pore in the outer membrane [Pugsley93]. Although Escherichia coli K-12 does not secrete endogenous proteins, the gsp genes of E. coli are orthologs of those in other secretons [Francetic96], including those of the pullulanase (pul) secretion pathway of Klebsiella oxytoca. The pulO gene product has been shown to be an enzyme required for processing of PulG as well as PulH, PulI and PulJ [Pugsley93a, Strom94]. Complementation studies have shown that the pulO homolog, gspO, is capable of complementing the processing function in a pulO deletion mutant [Francetic96]. The pulG homolog, gspG, has been shown to be capable of complementing a pulG mutation when expressed under the control of a lac promoter [Francetic96]. Transcription of the gspC-O operon was shown to be silenced in wild-type E. coli K-12 by the nucleoid structuring protein H-NS. Deletion mutants lacking H-NS and with the gsp genes present on a multiple-copy-number plasmid have been shown to express the secreton genes and promote the efficient secretion of the co-regulated endochitinase ChiA [Francetic00]. Expression of gspC-O also resulted in formation of pili composed of the GspG pseudopilin when extra copies of gspG were supplied on a second plasmid [Vignon03].

Sequence Features

Protein sequence of putative protein secretion protein for export with features indicated

Feature Class Location Citations Comment
Transmembrane-Region 7 -> 27
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


Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


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

Bleves98: Bleves S, Voulhoux R, Michel G, Lazdunski A, Tommassen J, Filloux A (1998). "The secretion apparatus of Pseudomonas aeruginosa: identification of a fifth pseudopilin, XcpX (GspK family)." Mol Microbiol 27(1);31-40. PMID: 9466253

Francetic00: Francetic O, Belin D, Badaut C, Pugsley AP (2000). "Expression of the endogenous type II secretion pathway in Escherichia coli leads to chitinase secretion." EMBO J 19(24);6697-703. PMID: 11118204

Francetic96: Francetic O, Pugsley AP (1996). "The cryptic general secretory pathway (gsp) operon of Escherichia coli K-12 encodes functional proteins." J Bacteriol 178(12);3544-9. PMID: 8655552

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."

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

Nunn93: Nunn DN, Lory S (1993). "Cleavage, methylation, and localization of the Pseudomonas aeruginosa export proteins XcpT, -U, -V, and -W." J Bacteriol 175(14);4375-82. PMID: 8331069

Okabe00: Okabe M, Kanzaki Y, Shimomura H, Terasaki F, Hayashi T, Kitaura Y (2000). "Images in cardiovascular medicine. Three-dimensional observation of the intracellular membrane structure in human myocardium: high-resolution scanning electron microscopy by the osmium-DMSO-osmium method." Circulation 101(19);2328-9. PMID: 10811603

Possot00: Possot OM, Vignon G, Bomchil N, Ebel F, Pugsley AP (2000). "Multiple interactions between pullulanase secreton components involved in stabilization and cytoplasmic membrane association of PulE." J Bacteriol 182(8);2142-52. PMID: 10735856

Pugsley93: Pugsley AP (1993). "The complete general secretory pathway in gram-negative bacteria." Microbiol Rev 57(1);50-108. PMID: 8096622

Pugsley93a: Pugsley AP (1993). "Processing and methylation of PuIG, a pilin-like component of the general secretory pathway of Klebsiella oxytoca." Mol Microbiol 9(2);295-308. PMID: 8412682

Pugsley98: Pugsley AP, Francetic O (1998). "Protein secretion in Escherichia coli K-12: dead or alive?." Cell Mol Life Sci 54(4);347-52. PMID: 9614971

Strom94: Strom MS, Nunn DN, Lory S (1994). "Posttranslational processing of type IV prepilin and homologs by PilD of Pseudomonas aeruginosa." Methods Enzymol 235;527-40. PMID: 8057924

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 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."

Vignon03: Vignon G, Kohler R, Larquet E, Giroux S, Prevost MC, Roux P, Pugsley AP (2003). "Type IV-like pili formed by the type II secreton: specificity, composition, bundling, polar localization, and surface presentation of peptides." J Bacteriol 185(11);3416-28. PMID: 12754241

Voulhoux01: Voulhoux R, Ball G, Ize B, Vasil ML, Lazdunski A, Wu LF, Filloux A (2001). "Involvement of the twin-arginine translocation system in protein secretion via the type II pathway." EMBO J 20(23);6735-41. PMID: 11726509

Other References Related to Gene Regulation

Chen07: Chen Z, Lewis KA, Shultzaberger RK, Lyakhov IG, Zheng M, Doan B, Storz G, Schneider TD (2007). "Discovery of Fur binding site clusters in Escherichia coli by information theory models." Nucleic Acids Res 35(20);6762-77. PMID: 17921503

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 Sat Oct 10, 2015, biocyc13.