메뉴 건너뛰기




Volumn 3, Issue 1, 2014, Pages 30-40

Enhancing tolerance to short-chain alcohols by engineering the Escherichia coli AcrB efflux pump to secrete the non-native substrate n-butanol

Author keywords

Biofuels; Directed evolution; Efflux pump; Protein engineering; Tolerance; Transporter

Indexed keywords

ACRB PROTEIN; BACTERIAL PROTEIN; BIOFUEL; BUTANOL; CARRIER PROTEIN; ISOBUTANOL; UNCLASSIFIED DRUG; ACRB PROTEIN, E COLI; ESCHERICHIA COLI PROTEIN; MULTIDRUG RESISTANCE PROTEIN;

EID: 84896129574     PISSN: None     EISSN: 21615063     Source Type: Journal    
DOI: 10.1021/sb400065q     Document Type: Article
Times cited : (96)

References (56)
  • 1
    • 84875935395 scopus 로고    scopus 로고
    • Land-use change and greenhouse gas emissions from corn and cellulosic ethanol
    • Dunn, J. B., Mueller, S., Kwon, H., and Wang, M. Q. (2013) Land-use change and greenhouse gas emissions from corn and cellulosic ethanol. Biotechnol. Biofuels 6, 51.
    • (2013) Biotechnol. Biofuels , vol.6 , pp. 51
    • Dunn, J.B.1    Mueller, S.2    Kwon, H.3    Wang, M.Q.4
  • 2
    • 84897096286 scopus 로고    scopus 로고
    • Sustainability impacts of first-generation biofuels
    • Gasparatos, A., Stromberg, P., and Takeuchi, K. (2013) Sustainability impacts of first-generation biofuels. Anim. Front. 3, 12-26.
    • (2013) Anim. Front. , vol.3 , pp. 12-26
    • Gasparatos, A.1    Stromberg, P.2    Takeuchi, K.3
  • 3
    • 84874740247 scopus 로고    scopus 로고
    • Renewable resources: Build a biomass energy market
    • Kopetz, H. (2013) Renewable resources: Build a biomass energy market. Nature 494, 29-31.
    • (2013) Nature , vol.494 , pp. 29-31
    • Kopetz, H.1
  • 6
    • 84858958694 scopus 로고    scopus 로고
    • Engineering Escherichia coli for succinate production from hemicellulose via consolidated bioprocessing
    • Zheng, Z., Chen, T., Zhao, M., Wang, Z., and Zhao, X. (2012) Engineering Escherichia coli for succinate production from hemicellulose via consolidated bioprocessing. Microb. Cell Fact. 11, 37.
    • (2012) Microb. Cell Fact. , vol.11 , pp. 37
    • Zheng, Z.1    Chen, T.2    Zhao, M.3    Wang, Z.4    Zhao, X.5
  • 7
    • 38049001166 scopus 로고    scopus 로고
    • Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels
    • Atsumi, S., Hanai, T., and Liao, J. C. (2008) Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. Nature 451, 86-89.
    • (2008) Nature , vol.451 , pp. 86-89
    • Atsumi, S.1    Hanai, T.2    Liao, J.C.3
  • 8
    • 33845442201 scopus 로고    scopus 로고
    • Engineering yeast transcription machinery for improved ethanol tolerance and production
    • Alper, H., Moxley, J., Nevoigt, E., Fink, G. R., and Stephanopoulos, G. (2006) Engineering yeast transcription machinery for improved ethanol tolerance and production. Science 314, 1565-1568.
    • (2006) Science , vol.314 , pp. 1565-1568
    • Alper, H.1    Moxley, J.2    Nevoigt, E.3    Fink, G.R.4    Stephanopoulos, G.5
  • 9
    • 84865142847 scopus 로고    scopus 로고
    • Microbial engineering for the production of advanced biofuels
    • Peralta-Yahya, P. P., Zhang, F., del Cardayre, S. B., and Keasling, J. D. (2012) Microbial engineering for the production of advanced biofuels. Nature 488, 320-328.
    • (2012) Nature , vol.488 , pp. 320-328
    • Peralta-Yahya, P.P.1    Zhang, F.2    Del Cardayre, S.B.3    Keasling, J.D.4
  • 10
    • 33846950348 scopus 로고    scopus 로고
    • Challenges in engineering microbes for biofuels production
    • Stephanopoulos, G. (2007) Challenges in engineering microbes for biofuels production. Science 315, 801-804.
    • (2007) Science , vol.315 , pp. 801-804
    • Stephanopoulos, G.1
  • 11
    • 80052807372 scopus 로고    scopus 로고
    • Role of alcohols in growth, lipid composition, and membrane fluidity of yeasts, bacteria, and archaea
    • Huffer, S., Clark, M. E., Ning, J. C., Blanch, H. W., and Clark, D. S. (2011) Role of alcohols in growth, lipid composition, and membrane fluidity of yeasts, bacteria, and archaea. Appl. Environ. Microbiol. 77, 694-11.
    • (2011) Appl. Environ. Microbiol. , vol.77 , pp. 694-711
    • Huffer, S.1    Clark, M.E.2    Ning, J.C.3    Blanch, H.W.4    Clark, D.S.5
  • 12
    • 84871402855 scopus 로고    scopus 로고
    • Engineering improved ethanol production in Escherichia coli with a genome-wide approach
    • Woodruff, L. B. A., Boyle, N. R., and Gill, R. T. (2013) Engineering improved ethanol production in Escherichia coli with a genome-wide approach. Metab. Eng. 15, 124-133.
    • (2013) Metab. Eng. , vol.15 , pp. 124-133
    • Woodruff, L.B.A.1    Boyle, N.R.2    Gill, R.T.3
  • 13
    • 80053172430 scopus 로고    scopus 로고
    • Engineering microbes for tolerance to next-generation biofuels
    • Dunlop, M. J. (2011) Engineering microbes for tolerance to next-generation biofuels. Biotechnol. Biofuels 4, 32.
    • (2011) Biotechnol. Biofuels , vol.4 , pp. 32
    • Dunlop, M.J.1
  • 15
    • 77955852574 scopus 로고    scopus 로고
    • A model for improving microbial biofuel production using a synthetic feedback loop
    • Dunlop, M. J., Keasling, J. D., and Mukhopadhyay, A. (2010) A model for improving microbial biofuel production using a synthetic feedback loop. Syst. Synth. Biol. 4, 95-104.
    • (2010) Syst. Synth. Biol. , vol.4 , pp. 95-104
    • Dunlop, M.J.1    Keasling, J.D.2    Mukhopadhyay, A.3
  • 16
    • 0033710214 scopus 로고    scopus 로고
    • The solvent efflux system of Pseudomonas putida S12 is not involved in antibiotic resistance
    • Isken, S., and Bont, J. A. M. D. (2000) The solvent efflux system of Pseudomonas putida S12 is not involved in antibiotic resistance. Appl. Microbiol. Biotechnol. 54, 711-714.
    • (2000) Appl. Microbiol. Biotechnol. , vol.54 , pp. 711-714
    • Isken, S.1    Bont, J.A.M.D.2
  • 18
    • 84864190737 scopus 로고    scopus 로고
    • Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation
    • Teixeira, M. C., Godinho, C. P., Cabrito, T. R., Mira, N. P., and Sá-Correia, I. (2012) Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation. Microb. Cell Fact. 11, 98.
    • (2012) Microb. Cell Fact. , vol.11 , pp. 98
    • Teixeira, M.C.1    Godinho, C.P.2    Cabrito, T.R.3    Mira, N.P.4    Sá-Correia, I.5
  • 19
    • 79952910616 scopus 로고    scopus 로고
    • Enzyme mechanism as a kinetic control element for designing synthetic biofuel pathways
    • Bond-Watts, B. B., Bellerose, R. J., and Chang, M. C. Y. (2011) Enzyme mechanism as a kinetic control element for designing synthetic biofuel pathways. Nat. Chem. Biol. 7, 222-227.
    • (2011) Nat. Chem. Biol. , vol.7 , pp. 222-227
    • Bond-Watts, B.B.1    Bellerose, R.J.2    Chang, M.C.Y.3
  • 21
    • 84874818199 scopus 로고    scopus 로고
    • Transporter engineering for improved tolerance against alkane biofuels in Saccharomyces cerevisiae
    • Chen, B., Ling, H., and Chang, M. W. (2013) Transporter engineering for improved tolerance against alkane biofuels in Saccharomyces cerevisiae. Biotechnol. Biofuels 6, 21.
    • (2013) Biotechnol. Biofuels , vol.6 , pp. 21
    • Chen, B.1    Ling, H.2    Chang, M.W.3
  • 22
    • 84877878130 scopus 로고    scopus 로고
    • Directed evolution of an E. Coli inner membrane transporter for improved efflux of biofuel molecules
    • Foo, J. L., and Leong, S. S. (2013) Directed evolution of an E. coli inner membrane transporter for improved efflux of biofuel molecules. Biotechnol. Biofuels 6, 81.
    • (2013) Biotechnol. Biofuels , vol.6 , pp. 81
    • Foo, J.L.1    Leong, S.S.2
  • 24
    • 79957568510 scopus 로고    scopus 로고
    • Structure and mechanism of RND-type multidrug efflux pumps
    • (Toone, E. J., Ed.). John Wiley & Sons, Inc., New York
    • Nikaido, H. (2011) Structure and mechanism of RND-type multidrug efflux pumps. In Adv. Enzymol. Relat. Areas Mol. Biol. (Toone, E. J., Ed.), pp 1-60. John Wiley & Sons, Inc., New York.
    • (2011) Adv. Enzymol. Relat. Areas Mol. Biol. , pp. 1-60
    • Nikaido, H.1
  • 25
    • 77951074736 scopus 로고    scopus 로고
    • Mechanism of recognition of compounds of diverse structures by the multidrug efflux pump AcrB of Escherichia coli
    • Takatsuka, Y., Chen, C., and Nikaido, H. (2010) Mechanism of recognition of compounds of diverse structures by the multidrug efflux pump AcrB of Escherichia coli. Proc. Natl. Acad. Sci. U.S.A. 107, 6559-6565.
    • (2010) Proc. Natl. Acad. Sci. U.S.A. , vol.107 , pp. 6559-6565
    • Takatsuka, Y.1    Chen, C.2    Nikaido, H.3
  • 27
    • 0036889033 scopus 로고    scopus 로고
    • Substrate specificity of the RND-type multidrug efflux pumps AcrB and AcrD of Escherichia coli is determined predominately by two large periplasmic loops
    • Elkins, C. A., and Nikaido, H. (2002) Substrate specificity of the RND-type multidrug efflux pumps AcrB and AcrD of Escherichia coli is determined predominately by two large periplasmic loops. J. Bacteriol. 184, 6490-6498.
    • (2002) J. Bacteriol. , vol.184 , pp. 6490-6498
    • Elkins, C.A.1    Nikaido, H.2
  • 28
    • 0038670226 scopus 로고    scopus 로고
    • Structural basis of multiple drug-binding capacity of the AcrB multidrug efflux pump
    • Yu, E. W., McDermott, G., Zgurskaya, H. I., Nikaido, H., and Koshland, D. E. (2003) Structural basis of multiple drug-binding capacity of the AcrB multidrug efflux pump. Science 300, 976-980.
    • (2003) Science , vol.300 , pp. 976-980
    • Yu, E.W.1    McDermott, G.2    Zgurskaya, H.I.3    Nikaido, H.4    Koshland, D.E.5
  • 30
    • 0030951186 scopus 로고    scopus 로고
    • Molecular evolution of an arsenate detoxification pathway by DNA shuffling
    • Crameri, A., Dawes, G., Rodriguez, E., Silver, S., and Stemmer, W. P. C. (1997) Molecular evolution of an arsenate detoxification pathway by DNA shuffling. Nat. Biotechnol. 15, 436-438.
    • (1997) Nat. Biotechnol. , vol.15 , pp. 436-438
    • Crameri, A.1    Dawes, G.2    Rodriguez, E.3    Silver, S.4    Stemmer, W.P.C.5
  • 31
    • 33748759588 scopus 로고    scopus 로고
    • Directed evolution of a bacterial efflux pump: Adaptation of the E. Coli TolC exit duct to the Pseudomonas MexAB translocase
    • Bokma, E., Koronakis, E., Lobedanz, S., Hughes, C., and Koronakis, V. (2006) Directed evolution of a bacterial efflux pump: Adaptation of the E. coli TolC exit duct to the Pseudomonas MexAB translocase. FEBS Lett. 580, 5339-5343.
    • (2006) FEBS Lett. , vol.580 , pp. 5339-5343
    • Bokma, E.1    Koronakis, E.2    Lobedanz, S.3    Hughes, C.4    Koronakis, V.5
  • 32
    • 38749137423 scopus 로고    scopus 로고
    • Fitting periplasmic membrane fusion proteins to inner membrane transporters: Mutations that enable Escherichia coli AcrA to function with Pseudomonas aeruginosa MexB
    • Krishnamoorthy, G., Tikhonova, E. B., and Zgurskaya, H. I. (2008) Fitting periplasmic membrane fusion proteins to inner membrane transporters: Mutations that enable Escherichia coli AcrA to function with Pseudomonas aeruginosa MexB. J. Bacteriol. 190, 691-698.
    • (2008) J. Bacteriol. , vol.190 , pp. 691-698
    • Krishnamoorthy, G.1    Tikhonova, E.B.2    Zgurskaya, H.I.3
  • 33
    • 0029018327 scopus 로고
    • Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter
    • Guzman, L. M., Belin, D., Carson, M. J., and Beckwith, J. (1995) Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter. J. Bacteriol. 177, 4121-4130.
    • (1995) J. Bacteriol. , vol.177 , pp. 4121-4130
    • Guzman, L.M.1    Belin, D.2    Carson, M.J.3    Beckwith, J.4
  • 34
    • 25144504245 scopus 로고    scopus 로고
    • A Periplasmic drug-binding site of the AcrB multidrug efflux pump: A crystallographic and site-directed mutagenesis study
    • Yu, E. W., Aires, J. R., McDermott, G., and Nikaido, H. (2005) A Periplasmic drug-binding site of the AcrB multidrug efflux pump: A crystallographic and site-directed mutagenesis study. J. Bacteriol. 187, 6804-6815.
    • (2005) J. Bacteriol. , vol.187 , pp. 6804-6815
    • Yu, E.W.1    Aires, J.R.2    McDermott, G.3    Nikaido, H.4
  • 36
    • 33748670458 scopus 로고    scopus 로고
    • Crystal structures of a multidrug transporter reveal a functionally rotating mechanism
    • Murakami, S., Nakashima, R., Yamashita, E., Matsumoto, T., and Yamaguchi, A. (2006) Crystal structures of a multidrug transporter reveal a functionally rotating mechanism. Nature 443, 173-179.
    • (2006) Nature , vol.443 , pp. 173-179
    • Murakami, S.1    Nakashima, R.2    Yamashita, E.3    Matsumoto, T.4    Yamaguchi, A.5
  • 37
    • 33748310520 scopus 로고    scopus 로고
    • Structural asymmetry of AcrB trimer suggests a peristaltic pump mechanism
    • Seeger, M. A., Schiefner, A., Eicher, T., Verrey, F., Diederichs, K., and Pos, K. M. (2006) Structural asymmetry of AcrB trimer suggests a peristaltic pump mechanism. Science 313, 1295-1298.
    • (2006) Science , vol.313 , pp. 1295-1298
    • Seeger, M.A.1    Schiefner, A.2    Eicher, T.3    Verrey, F.4    Diederichs, K.5    Pos, K.M.6
  • 38
    • 0023654076 scopus 로고
    • In vitro translocation of protein across Escherichia coli membrane vesicles requires both the proton motive force and ATP
    • Yamane, K., Ichihara, S., and Mizushima, S. (1987) In vitro translocation of protein across Escherichia coli membrane vesicles requires both the proton motive force and ATP. J. Biol. Chem. 262, 2358-2362.
    • (1987) J. Biol. Chem. , vol.262 , pp. 2358-2362
    • Yamane, K.1    Ichihara, S.2    Mizushima, S.3
  • 39
    • 0021691383 scopus 로고
    • The kinetic mechanism by which CCCP (carbonyl cyanidem- chlorophenylhydrazone) transports protons across membranes
    • Kasianowicz, J., Benz, R., and McLaughlin, S. (1984) The kinetic mechanism by which CCCP (carbonyl cyanidem-chlorophenylhydrazone) transports protons across membranes. J. Membr. Biol. 82, 179-190.
    • (1984) J. Membr. Biol. , vol.82 , pp. 179-190
    • Kasianowicz, J.1    Benz, R.2    McLaughlin, S.3
  • 40
    • 33749630424 scopus 로고    scopus 로고
    • Threonine-978 in the transmembrane segment of the multidrug efflux pump AcrB of Escherichia coli is crucial for drug transport as a probable component of the proton relay network
    • Takatsuka, Y., and Nikaido, H. (2006) Threonine-978 in the transmembrane segment of the multidrug efflux pump AcrB of Escherichia coli is crucial for drug transport as a probable component of the proton relay network. J. Bacteriol. 188, 7284-7289.
    • (2006) J. Bacteriol. , vol.188 , pp. 7284-7289
    • Takatsuka, Y.1    Nikaido, H.2
  • 41
    • 67649583295 scopus 로고    scopus 로고
    • Crucial role of Asp408 in the proton translocation pathway of multidrug transporter AcrB: Evidence from Site-directed mutagenesis and carbodiimide labeling
    • Seeger, M. A., von Ballmoos, C., Verrey, F., and Pos, K. M. (2009) Crucial role of Asp408 in the proton translocation pathway of multidrug transporter AcrB: Evidence from Site-directed mutagenesis and carbodiimide labeling. Biochemistry 48, 5801-5812.
    • (2009) Biochemistry , vol.48 , pp. 5801-5812
    • Seeger, M.A.1    Von Ballmoos, C.2    Verrey, F.3    Pos, K.M.4
  • 42
    • 33746606073 scopus 로고    scopus 로고
    • Outer membrane vesicle production by Escherichia coli Is independent of membrane instability
    • McBroom, A. J., Johnson, A. P., Vemulapalli, S., and Kuehn, M. J. (2006) Outer membrane vesicle production by Escherichia coli Is independent of membrane instability. J. Bacteriol. 188, 5385-5392.
    • (2006) J. Bacteriol. , vol.188 , pp. 5385-5392
    • McBroom, A.J.1    Johnson, A.P.2    Vemulapalli, S.3    Kuehn, M.J.4
  • 44
    • 84862853727 scopus 로고    scopus 로고
    • Engineering global transcription factor cyclic AMP receptor protein of Escherichia coli for improved 1-butanol tolerance
    • Zhang, H., Chong, H., Ching, C. B., Song, H., and Jiang, R. (2012) Engineering global transcription factor cyclic AMP receptor protein of Escherichia coli for improved 1-butanol tolerance. Appl. Microbiol. Biotechnol. 94, 1107-1117.
    • (2012) Appl. Microbiol. Biotechnol. , vol.94 , pp. 1107-1117
    • Zhang, H.1    Chong, H.2    Ching, C.B.3    Song, H.4    Jiang, R.5
  • 45
    • 79952589723 scopus 로고    scopus 로고
    • Engineering butanol-tolerance in Escherichia coli with artificial transcription factor libraries
    • Lee, J. Y., Yang, K. S., Jang, S. A., Sung, B. H., and Kim, S. C. (2011) Engineering butanol-tolerance in Escherichia coli with artificial transcription factor libraries. Biotechnol. Bioeng. 108, 742-749.
    • (2011) Biotechnol. Bioeng. , vol.108 , pp. 742-749
    • Lee, J.Y.1    Yang, K.S.2    Jang, S.A.3    Sung, B.H.4    Kim, S.C.5
  • 46
    • 84868351277 scopus 로고    scopus 로고
    • Toward a semisynthetic stress response system to engineer microbial solvent tolerance
    • Zingaro, K. A., and Papoutsakis, E. T. (2012) Toward a semisynthetic stress response system to engineer microbial solvent tolerance. mBio 3, 308-312.
    • (2012) MBio , vol.3 , pp. 308-312
    • Zingaro, K.A.1    Papoutsakis, E.T.2
  • 47
    • 79952432805 scopus 로고    scopus 로고
    • Genomic library screens for genes involved in n-butanol tolerance in Escherichia coli
    • Reyes, L. H., Almario, M. P., and Kao, K. C. (2011) Genomic library screens for genes involved in n-butanol tolerance in Escherichia coli. PLoS One 6, e17678.
    • (2011) PLoS One , vol.6
    • Reyes, L.H.1    Almario, M.P.2    Kao, K.C.3
  • 48
    • 84865711025 scopus 로고    scopus 로고
    • Visualizing evolution in real time to determine the molecular mechanisms of n-butanol tolerance in Escherichia coli
    • Reyes, L. H., Almario, M. P., Winkler, J., Orozco, M. M., and Kao, K. C. (2012) Visualizing evolution in real time to determine the molecular mechanisms of n-butanol tolerance in Escherichia coli. Metab. Eng. 14, 579-590.
    • (2012) Metab. Eng. , vol.14 , pp. 579-590
    • Reyes, L.H.1    Almario, M.P.2    Winkler, J.3    Orozco, M.M.4    Kao, K.C.5
  • 49
    • 84875542878 scopus 로고    scopus 로고
    • Towards a metabolic engineering strain "commons": An Escherichia coli platform strain for ethanol production
    • Woodruff, L. B. A., May, B. L., Warner, J. R., and Gill, R. T. (2013) Towards a metabolic engineering strain "commons": An Escherichia coli platform strain for ethanol production. Biotechnol. Bioeng. 110, 1520-1526.
    • (2013) Biotechnol. Bioeng. , vol.110 , pp. 1520-1526
    • Woodruff, L.B.A.1    May, B.L.2    Warner, J.R.3    Gill, R.T.4
  • 50
    • 0034612342 scopus 로고    scopus 로고
    • One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products
    • Datsenko, K. A., and Wanner, B. L. (2000) One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products. Proc. Natl. Acad. Sci. U.S.A. 97, 6640-6645.
    • (2000) Proc. Natl. Acad. Sci. U.S.A. , vol.97 , pp. 6640-6645
    • Datsenko, K.A.1    Wanner, B.L.2
  • 51
    • 68149136937 scopus 로고    scopus 로고
    • Circular polymerase extension cloning of complex gene libraries and pathways
    • Quan, J., and Tian, J. (2009) Circular polymerase extension cloning of complex gene libraries and pathways. PLoS One 4, e6441.
    • (2009) PLoS One , vol.4
    • Quan, J.1    Tian, J.2
  • 52
    • 79551667941 scopus 로고    scopus 로고
    • Circular polymerase extension cloning for high-throughput cloning of complex and combinatorial DNA libraries
    • Quan, J., and Tian, J. (2011) Circular polymerase extension cloning for high-throughput cloning of complex and combinatorial DNA libraries. Nat. Protoc. 6, 242-251.
    • (2011) Nat. Protoc. , vol.6 , pp. 242-251
    • Quan, J.1    Tian, J.2
  • 55
    • 0025291747 scopus 로고
    • Flow cytometric identification of microorganisms by dual staining with FITC and PI
    • Miller, J., and Quarles, J. (1990) Flow cytometric identification of microorganisms by dual staining with FITC and PI. Cytometry 11, 667-75.
    • (1990) Cytometry , vol.11 , pp. 667-675
    • Miller, J.1    Quarles, J.2
  • 56
    • 0034756555 scopus 로고    scopus 로고
    • Production of correctly folded Fab antibody fragment in the cytoplasm of Escherichia coli trxB gor mutants via the coexpression of molecular chaperones
    • Levy, R., Weiss, R., Chen, G., Iverson, B. L., and Georgiou, G. (2001) Production of correctly folded Fab antibody fragment in the cytoplasm of Escherichia coli trxB gor mutants via the coexpression of molecular chaperones. Protein Expression Purif. 23, 338-347.
    • (2001) Protein Expression Purif. , vol.23 , pp. 338-347
    • Levy, R.1    Weiss, R.2    Chen, G.3    Iverson, B.L.4    Georgiou, G.5


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.