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A. Yamaguchi, T. Akasaka, N. Ono, Y. Someya, M. Nakatani, T. Sawai (1992)
Metal-tetracycline/H+ antiporter of Escherichia coli encoded by transposon Tn10. Roles of the aspartyl residues located in the putative transmembrane helices.The Journal of biological chemistry, 267 11
H. Gutfreund (1975)
Enzyme kineticsNature, 258
A. Jessen-Marshall, Nanette Paul, R. Brooker (1995)
The Conserved Motif, GXXX(D/E)(R/K)XG[X](R/K)(R/K), in Hydrophilic Loop 2/3 of the Lactose Permease (*)The Journal of Biological Chemistry, 270
A. Jessen-Marshall, N. Parker, R. Brooker (1997)
Suppressor analysis of mutations in the loop 2-3 motif of lactose permease: evidence that glycine-64 is an important residue for conformational changesJournal of Bacteriology, 179
Foster Dl, Miloslav Boublik, Kaback Hr (1983)
Structure of the lac carrier protein of Escherichia coli.The Journal of biological chemistry, 258 1
R. Brooker, T. Wilson (1985)
Isolation and nucleotide sequencing of lactose carrier mutants that transport maltose.Proceedings of the National Academy of Sciences of the United States of America, 82 12
(1984)
Monoclonal antibodies against the lac carrier protein fromEscherichia coli. Binding studies with membrane vesicles and proteoliposomes reconstituted with purified lac carrier protein.Biochemistry
J. Calamia, C. Manoil (1992)
Membrane protein spanning segments as export signals.Journal of molecular biology, 224 3
J. Sambrook, E. Fritsch, T. Maniatis (2001)
Molecular Cloning: A Laboratory Manual
Jeffrey Griffith, Michael Baker, Duncan Rouch, Malcolm Page, Ronald Skurray, Ian Paulsen, K. Chater, Stephen Baldwin, Peter Henderson (1992)
Membrane transport proteins: implications of sequence comparisons.Current opinion in cell biology, 4 4
(1996)
Evidence that the conserved motif, G-X-X-X-D/E-R/K-X-G-[X]-R/K-R/K, in hydrophilic loop 2-3 affects a conformationally-sensitive interface between the two halves of the lactose permease
A. Yamaguchi, Y. Someya, T. Sawai (1992)
Metal-tetracycline/H+ antiporter of Escherichia coli encoded by transposon Tn10. The role of a conserved sequence motif, GXXXXRXGRR, in a putative cytoplasmic loop between helices 2 and 3.The Journal of biological chemistry, 267 27
P. Henderson, M. Maiden (1990)
Homologous sugar transport proteins in Escherichia coli and their relatives in both prokaryotes and eukaryotes.Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 326 1236
I. West, P. Mitchell (1973)
Stoicheiometry of lactose-H+ symport across the plasma membrane of Escherichia coli.The Biochemical journal, 132 3
Tomomi Kimura, Youko Inagaki, T. Sawai, Akihito Yamaguchi (1995)
Substrate‐induced acceleration of N‐ethylmaleimide reaction with the Cys‐65 mutant of the transposon Tn 10‐encoded metal‐tetracycline/H+ antiporter depends on the interaction of Asp‐66 with the substrateFEBS Letters, 362
V. Goswitz, R. Brooker (1995)
Structural features of the uniporter/symporter/antiporter superfamilyProtein Science, 4
M. Maiden, E. Davis, S. Baldwin, D. Moore, P. Henderson (1987)
Mammalian and bacterial sugar transport proteins are homologousNature, 325
Ron Teather, John Bramhall, I. Riede, J. Wright, Monika Furst, G. Aichele, U. Wilhelm, Peter Overath (1980)
Lactose carrier protein of Escherichia coli. Structure and expression of plasmids carrying the Y gene of the lac operon.European journal of biochemistry, 108 1
Akihito Yamaguchi, Tomomi Kimura, Y. Someya, T. Sawai (1993)
Metal-tetracycline/H+ antiporter of Escherichia coli encoded by transposon Tn10. The structural resemblance and functional difference in the role of the duplicated sequence motif between hydrophobic segments 2 and 3 and segments 8 and 9.The Journal of biological chemistry, 268 9
M. Mandel, A. Higa (1990)
Calcium-dependent Bacteriophage DNA Infection
J. Calamia, Colin Manoil (1990)
lac permease of Escherichia coli: topology and sequence elements promoting membrane insertion.Proceedings of the National Academy of Sciences of the United States of America, 87 13
T. Kunkel (1985)
Rapid and efficient site-specific mutagenesis without phenotypic selection.Proceedings of the National Academy of Sciences of the United States of America, 82 2
(1987)
Rapid and efficient site-specific mutagenesis without phenotypic selection. Methods Enzymol
Robert Kraft, J. Tardiff, Kenneth Krauter, L. Leinwand (1988)
Using mini-prep plasmid DNA for sequencing double stranded templates with Sequenase.BioTechniques, 6 6
D. Herzlinger, P. Viitanen, N. Carrasco, H. Kaback (1984)
Monoclonal antibodies against the lac carrier protein from Escherichia coli. 2. Binding studies with membrane vesicles and proteoliposomes reconstituted with purified lac carrier protein.Biochemistry, 23 16
N. Pazdernik, Shane Cain, R. Brooker (1997)
An Analysis of Suppressor Mutations Suggests That the Two Halves of the Lactose Permease Function in a Symmetrical Manner*The Journal of Biological Chemistry, 272
J. Sun, J. Li, N. Carrasco, H. Kaback (1997)
The last two cytoplasmic loops in the lactose permease of Escherichia coli comprise a discontinuous epitope for a monoclonal antibody.Biochemistry, 36 1
G. Heijne, C. Manoil (1990)
Membrane proteins: from sequence to structure.Protein engineering, 4 2
M. Zoller, M. Smith (1983)
Oligonucleotide-directed mutagenesis of DNA fragments cloned into M13 vectors.Methods in enzymology, 100
S. Pao, I. Paulsen, M. Saier (1998)
Major Facilitator SuperfamilyMicrobiology and Molecular Biology Reviews, 62
H. Kaback, K. Jung, H. Jung, Jianhua Wu, G. Privé, K. Zen (1993)
What's new with lactose permeaseJournal of Bioenergetics and Biomembranes, 25
P. Henderson (1990)
Proton-linked sugar transport systems in bacteriaJournal of Bioenergetics and Biomembranes, 22
I. West (1970)
Lactose transport coupled to proton movements in Escherichia coli.Biochemical and biophysical research communications, 41 3
Nancy Carrasco, Stanley Tahara, Lekha Patel, T. Goldkorn, H. Kaback (1982)
Preparation, characterization, and properties of monoclonal antibodies against the lac carrier protein from Escherichia coli.Proceedings of the National Academy of Sciences of the United States of America, 79 22
D. Büchel, B. Gronenborn, B. Müller-Hill (1980)
Sequence of the lactose permease geneNature, 283
(1997)
Role of Conserved Residues in Hydrophilic Loop 8 - 9 the Lactose Perme
N. Pazdernik, A. Jessen-Marshall, R. Brooker (1997)
Role of conserved residues in hydrophilic loop 8-9 of the lactose permeaseJournal of Bacteriology, 179
H. Rickenberg, G. Cohen, G. Buttin, J. Monod (1978)
LA GALACTOSIDE-PERMÉASE D'ESCHERICHIA COLI *
(1985)
Improved M 13 phage cloning vectors and host strains : nucleotide sequences of the M 13 mp 18 and pUC 19 vectors
C. Yanisch-Perron, J. Vieira, J. Messing (1985)
Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors.Gene, 33 1
Jeffrey Miller (1972)
Experiments in molecular genetics
P. Franco, R. Brooker (1994)
Functional roles of Glu-269 and Glu-325 within the lactose permease of Escherichia coli.The Journal of biological chemistry, 269 10
The lactose permease is a polytopic membrane protein that has a duplicated conserved motif, GXXX(D/E)(R/K)XG[X](R/K)(R/K), located in cytoplasmic loops 2/3 and 8/9. In the current study, the roles of the basic residues and the acidic residue were investigated in greater detail. Neutral substitutions of two positive charges in loop 2/3 were tolerated, while a triple mutant resulted in a complete loss of expression. Neutral substitutions of a basic residue in loop 8/9 (i.e., K289I) also diminished protein stability. By comparison, neutral substitutions affecting the negative charge in loop 2/3 had normal levels of expression, but were defective in transport. A double mutant (D68T/N284D), in which the aspartate of loop 2/3 was moved to loop 8/9, did not have appreciable activity, indicating that the negative charge in the conserved motif could not be placed in loop 8/9 to recover lactose transport activity. An analysis of site-directed mutants in loop 7/8 and loop 8/9 indicated that an alteration in the charge distribution across transmembrane segment 8 was not sufficient to alleviate a defect caused by the loss of a negative charge in loop 2/3. To further explore this phenomenon, the double mutant, D68T/N284D, was used as a parental strain to isolate suppressor mutations which restored function. One mutant was obtained in which an acidic residue in loop 11/12 was changed to a basic residue (i.e., Glu-374 → Lys). Overall, the results of this study suggest that the basic residues in the conserved motif play a role in protein insertion and/or stability, and that the negative charge plays a role in conformational changes.
The Journal of Membrane Biology – Springer Journals
Published: Mar 1, 2000
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