tolC E.coli strain大肠杆菌菌株 BioVector NTCC质粒载体菌种细胞基因保藏中心

tolC E.coli strain大肠杆菌菌株 BioVector NTCC质粒载体菌种细胞基因保藏中心 gene tolC protein TolC outer membrane channel Add to SmartTable Escherichia coli K-12 substr. MG1655 twitter Synonyms weeA, colE1-i, mtcB, mukA, refI, toc Accession IDs EG11009 (EcoCyc) b3035 ECK3026 P02930 (UniProt) Length 1482 bp / 493 aa Map Position [3,178,115 -> 3,179,596] (68.47 centisomes, 246°) View in Genome Browser Location outer membrane Reactions transport of a macrolide antibiotic (catalyzed by complex) transport of chenodeoxycholate (catalyzed by complex) Transport of enterobactin (catalyzed by complex) transport of a drug (catalyzed by complex) Evidence Inferred from experiment Inferred from direct assay [Thanabalu98] Inferred from mutant phenotype [Wandersman90] SummaryGO Terms (15)EssentialityReactions (4)Protein FeaturesOperonsReferencesShow All Regulation Summary Diagram Summary TolC is an outer membrane porin involved in the efflux of several hydrophobic and amphipathic molecules. TolC functions as a trimer and is a common outer membrane component of several multi-drug efflux systems. The tolC gene product localises to the outer membrane [Morona83]. TolC was purified from the Escherichia coli outer membrane as a trimer and its structure was determined by two dimensional projection at a resolution of 12 Å. TolC was found to be an outer membrane protein with each monomer comprising a membrane domain, predicted to be beta-barrel, and a C-terminal periplasmic domain [Koronakis97]. Targeting of TolC to the Sec-translocase for transport across the inner membrane is SecB-dependent [Baars06]. The three dimensional crystal structure of TolC has been determined in an unbound state to a 2.1 Å resolution and in a ligand-bound complex to a 2.75 Å resolution. Each protomer of TolC contributes four β strands to the outer membrane β-barrel structure and four alpha helices to a contiguous α-helical barrel that extends into the periplasm [Koronakis00, Higgins04]. Reconstitution studies suggest that TolC is an outer membrane channel for peptides [Benz93]. TolC is required for the function of the AcrAB multidrug efflux system [Fralick96] and its homologs AcrEF [Kobayashi01] and YhiUV [Nishino02], the EmrAB drug efflux system [BorgesWalmsley03], the EmrAB homolog, EmrKY [Tanabe97], the MdtABC drug efflux system [Nagakubo02] and the MacAB macrolide extrusion system [Kobayashi01a]. Crystal structures of TolC mutants reveal partially open states of the porin and indicate regions which appear to be involved in binding the periplasmic component of ArcAB [Bavro08]. The mutant phenotype from growth assays suggest TolC is involved in export of thymine when thymidine is the sole carbon source, though an inner membrane export system has not yet been identified [Reed06]. Gene expression analyses indicate that tolC is essential for L-cysteine tolerance and that tolC overexpression is effective for L-cysteine production in E. coli cells [Wiriyathanawudh09]. Mutations in tolC result in a reduction in the synthesis of OmpF porin and an increase in the level of OmpC porin synthesis [Misra87]. Down regulation of tolC is observed under starvation conditions [Muela08]. TolC deficient E.coli cells show decreased growth rates and altered morphology when grown in glucose minimal media. This phenotype is exacerbated by lack of ybiBC and/or yjfMC [Dhamdhere10]. ΔtolC cells are morphologically abnormal - they are often longer and exhibit coccoid shaped bulges. The observed growth impairment and abnormal morhology can be complemented by tolC expressed in trans, by the addition of iron to the culture medium or by deleting any of the genes involved in enterobactin synthesis (entC, entA, entB, entE or entF). The morphological defects and growth impairment of ΔtolC cells grown in glucose minimal medium are due to the accumulation of enterobactin in the periplasm of E. coli K-12 [Vega14]. Reviews: [Koronakis04, Zgurskaya11] Additional Citations: [Vaccaro08, Lin08, Zhang08] Molecular Weight of Polypeptide 53.741 kD (from nucleotide sequence) Subunit Composition [TolC]3 Component of multidrug efflux pump MdtABC-TolC (extended summary available): [(TolC)3][MdtC][MdtB]2[MdtA] EntS-TolC enterobactin exporter (summary available): [EntS][(TolC)3] EmrKY-TolC multidrug efflux pump (summary available): [EmrK][EmrY][(TolC)3] EmrAB-TolC multidrug efflux pump (summary available): [EmrA][EmrB][(TolC)3] AcrEF-TolC multidrug efflux pump (summary available): [AcrE][AcrF]3[(TolC)3] AcrAD-TolC multidrug efflux pump (extended summary available): [AcrD]3[AcrA][(TolC)3] AcrAB-TolC multidrug efflux pump (extended summary available): [AcrA]6[(TolC)3][AcrB]3 MdtEF-TolC multidrug efflux pump (extended summary available): [(TolC)3][MdtE]3[MdtF]3 macrolide ABC exporter (extended summary available): [(TolC)3][MacB]2[MacA]6 [Supplier来源] http://www.biovector.net