Structure and Mechanism of the Lactose Permease of <i>Escherichia coli</i>
SciencePublished 31 July 2003
Jeff Abramson, И. Н. Смирнова, Vladimir N. Kasho, G. Verner, H. Ronald Kaback, So Iwata
Citations1,389
SJR quartileQ1
SJR score10.42
SNIP6.62
Generate an AI Snapshot to get a quick, structured summary of this paper.
Study Snapshot
ObjectiveStudy objective
MethodsResearch methodology
PopulationPopulation studied
Sample sizeSample sizes
OutcomesStudy outcomes here
ResultsStudy results comes here
LimitationsResearch study limitations comes here
A concise AI-generated summary of the paper will appear here once you click Generate AI Snapshot.
Abstract
Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins. We report the crystal structure at 3.5 angstroms of the Escherichia coli lactose permease, an intensively studied member of the major facilitator superfamily of transporters. The molecule is composed of N- and C-terminal domains, each with six transmembrane helices, symmetrically positioned within the permease. A large internal hydrophilic cavity open to the cytoplasmic side represents the inward-facing conformation of the transporter. The structure with a bound lactose homolog, beta-D-galactopyranosyl-1-thio-beta-D-galactopyranoside, reveals the sugar-binding site in the cavity, and residues that play major roles in substrate recognition and proton translocation are identified. We propose a possible mechanism for lactose/proton symport (co-transport) consistent with both the structure and a large body of experimental data.
Keywords
Materials ScienceBiochemistry, Genetics and Molecular Biology
ScienceClassical Electrostatics in Biology and Chemistry
2,889 Citations1995Barry Honig, Anthony Nicholls
ScienceThe Whole Structure of the 13-Subunit Oxidized Cytochrome c Oxidase at 2.8 Å
2,105 Citations1996Tomitake Tsukihara, Hiroshi Aoyama +7 more
Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains.
NatureCrystal structure of bacterial multidrug efflux transporter AcrB
977 Citations2002Satoshi Murakami, Ryosuke Nakashima +2 more
The crystal structure of AcrB implies that substrates translocated from the cell interior through the transmembrane region and from the periplasm through the vestibules are collected in the central cavity and then actively transported through the pore into the TolC tunnel.
The Journal of PhysiologyInability of diffusion to account for placental glucose transfer in the sheep and consideration of the kinetics of a possible carrier transfer
428 Citations1952W. F. Widdas
The FASEB JournalCys‐scanning mutagenesis: a novel approach to structure—function relationships in polytopic membrane proteins
357 Citations1998Stathis Frillingos, Miklós Sahin‐Tóth +2 more
The entire lactose permease of Escherichia coli, a polytopic membrane transport protein that catalyzes β‐galactoside/H+ symport, has been subjected to Cys‐scanning mutagenesis to determine which residues play an obligatory role in the mechanism and to create a library of mutants with a single‐Cys residue at each position of the molecule for structure/function studies.
Molecular MicrobiologyFamilies of transmembrane sugar transport proteins
307 Citations2000Milton H. Saier
Twenty families of secondary (pmf‐driven) carriers are described which, in addition to nine families within the ATP‐dependent ABC superfamily, and seven families of Gram‐negative bacterial outer membrane porins, largely account for the stereospecific transport of sugars and their derivatives into and out of all living cells on earth.
Journal of Biological ChemistryStructure of the lac carrier protein of Escherichia coli.
297 Citations1983David L. Foster, M. Boublík +1 more
It is proposed that the lac carrier protein consists of at least 12 alpha-helical segments that traverse the membrane in a perpendicular sense, i.e. in a fashion similar to bacteriorhodopsin.
Nature Reviews Molecular Cell BiologyThe kamikaze approach to membrane transport
288 Citations2001H. Ronald Kaback, Miklós Sahin‐Tóth +1 more
Novel approaches that have been developed and applied to one membrane transport protein, the lactose permease from Escherichia coli, are now being used to study various other membrane proteins.
Proceedings of the National Academy of Scienceslac permease of Escherichia coli: topology and sequence elements promoting membrane insertion.
245 Citations1990Justina C. Calamia, Colin Manoil
The alkaline phosphatase activities of cells expressing the lacY-phoA fusions distinguish between models previously proposed for the topology of lac permease and favor one with 12 transmembrane segments and is fully compatible with the results of earlier biochemical and immunological studies.
Journal of Molecular BiologyThermal motions of surface α-helices in the d-galactose chemosensory receptor
239 Citations1992Claire L. Careaga, Joseph J. Falke
A TV circuit for generating a synchronized horizontal frequency signal has an oscillator and a phase discriminator so as to eliminate the effects of temperature and voltage variations.
The Lac Operon: A Short History of a Genetic Paradigm
202 Citations1996Benno Müller‐Hill
A description of the history and present knowledge of a paradigmatic system, the lac operon of Escherichia coli, with a unique combination of personal anecdotes and present-day science is appealing to students, postdocs, active and retired researchers alike.
Journal of Bioenergetics and BiomembranesProton-linked sugar transport systems in bacteria
154 Citations1990Peter J. F. Henderson
In vivo andin vitro mutagenesis of the lactose/H+ and melibiose/Na+ (H+) transporters ofE.
Proceedings of the National Academy of SciencesFunctional interactions between putative intramembrane charged residues in the lactose permease of Escherichia coli.
121 Citations1992Miklós Sahin‐Tóth, R L Dunten +2 more
The data demonstrate that neither residue nor the salt bridge plays an important role in the transport mechanism, and suggest that putative transmembrane helix VII lies next to helices X and XI in the tertiary structure of lactose permease.
BiochemistryUse of site-directed fluorescence labeling to study proximity relationships in the lactose permease of Escherichia coli
112 Citations1993Kirsten Jung, Heinrich Jung +3 more
An approach to studying proximity relationships in lactose permease is described that is based upon site-directed pyrene labeling of combinations of paired Cys replacements in a mutant devoid of Cys residues, demonstrating that putative helices VIII and IX are close to helix X.
Journal of BacteriologyStructural Model for 12-Helix Transporters Belonging to the Major Facilitator Superfamily
107 Citations2003Teruhisa Hirai, Jurgen Heymann +2 more
This analysis narrows down the number of helix arrangements from about a billion starting possibilities to a single probable model for the relative spatial arrangement for the 12 helices, consistent with structural findings and with the majority of previous biochemical studies on members of this superfamily.
Proceedings of the National Academy of SciencesAn approach to membrane protein structure without crystals
84 Citations2002Paul L. Sorgen, Yonglin Hu +3 more
The lactose permease of Escherichia coli catalyzes coupled translocation of galactosides and H+ across the cell membrane and it is demonstrated that this information is sufficient to calculate a structural model at the level of helix packing or better.
Journal of Biological ChemistryFunctional roles of Glu-269 and Glu-325 within the lactose permease of Escherichia coli.
81 Citations1994Peter J. Franco, Robert J. Brooker
Results are consistent with the notion that an acidic residue at position 325 is required for H+ transport via the lactose permease.
BiochemistryA Mutation in the Lactose Permease of <i>Escherichia coli</i> That Decreases Conformational Flexibility and Increases Protein Stability
77 Citations2003И. Н. Смирнова, H. Ronald Kaback
The results indicate that the Cys154 --> Gly mutation causes a more compact structure and decreased conformational flexibility, an alteration that specifically blocks the structural changes necessary for substrate translocation with little or no effect on ligand binding.
Proceedings of the National Academy of SciencesFourier transform infrared spectroscopy reveals a rigid α-helical assembly for the tetrameric <i>Streptomyces lividans</i> K <sup>+</sup> channel
75 Citations1998Johannes le Coutre, H. Ronald Kaback +3 more
The structure of the tetrameric K+ channel from Streptomyces lividans in a lipid bilayer environment was studied by polarized attenuated total reflection Fourier transform infrared spectroscopy and results are discussed in relationship to the lactose permease of Escherichia coli, a membrane transport protein.
Proceedings of the National Academy of SciencesThe substrate-binding site in the lactose permease of <i>Escherichia coli</i>
70 Citations1998Pushpa Venkatesan, H. Ronald Kaback
It is demonstrated that Glu-126 and Arg-144 are irreplaceable for substrate binding and suggested a model for the substrate-binding site in the permease, consistent with the notion that alterations in the substrate translocation pathway at the interface between helices IV and V are transmitted conformationally to the H+.
BiochemistryAromatic Stacking in the Sugar Binding Site of the Lactose Permease
69 Citations2003Lan Guan, Yonglin Hu +1 more
It is demonstrated that Trp151 is an important component of the binding site, probably orienting the galactopyranosyl ring so that important H-bond interactions with side chains in helices IV, V, and VIII can be realized.
Proceedings of the National Academy of SciencesArg-302 facilitates deprotonation of Glu-325 in the transport mechanism of the lactose permease from <i>Escherichia coli</i>
61 Citations2001Miklós Sahin‐Tóth, H. Ronald Kaback
Observations lend strong support for the argument that Arg-302 interacts with Glu-325 to facilitate deprotonation of the carboxylic acid during turnover.
BiochemistryEngineering a Metal Binding Site within a Polytopic Membrane Protein, the Lactose Permease of Escherichia coli
60 Citations1995Kirsten Jung, John C. Voss +3 more
The results confirm the conclusion that helices VIII and X are closely opposed in the tertiary structure of lac permease and provide a novel approach for studying helix proximity, as well as solvent accessibility, in polytopic membrane proteins.
Molecular Membrane BiologyRole of glutamate-269 in the lactose permease of<i>Escherichia coli</i>
57 Citations1994M. L. Ujwal, Miklós Sahin‐Tóth +2 more
It is demonstrated that a carboxylate at position 269 is essential for transport activity, and Glu-269 is important for substrate binding and/or recognition in the lactose permease of Escherichia coli.
StructureStructural foundation for the design of receptor antagonists targeting Escherichia coli heat-labile enterotoxin
53 Citations1997E.A. Merritt, Steve Sarfaty +2 more
Four derivatives of the simple sugar galactose, members of a larger series of receptor antagonists identified by computer modeling and competitive binding studies, have been co-crystallized with either the full LT AB5 holotoxin or the LT B pentamer.
BiochemistryFourier Transform Infrared Analysis of Purified Lactose Permease: A Monodisperse Lactose Permease Preparation Is Stably Folded, α-Helical, and Highly Accessible to Deuterium Exchange
53 Citations1998Jason S. Patzlaff, Jeffrey A. Moeller +2 more
Results suggest that the monodisperse lactose permease is conformationally flexible and that 2H exchange is facilitated as the result of conformational fluctuations from the folded state.
BiochemistryProximity between Glu126 and Arg144 in the Lactose Permease of <i>Escherichia coli</i>
51 Citations1999Min Zhao, Kuo‐Chang Zen +2 more
Three different site-directed spectroscopic techniques were applied to permease mutants in which Glu 126 and/or Arg144 were replaced with either His or Cys residues, providing strong support for the conclusion that Glu126 (helix IV) and Arg144 (helIX V) are in close physical proximity.
Proceedings of the National Academy of SciencesSurface-exposed positions in the transmembrane helices of the lactose permease of <i>Escherichia coli</i> determined by intermolecular thiol cross-linking
48 Citations2002Lan Guan, Franklin D. Murphy +1 more
The findings confirm previous observations indicating that intermolecular cross-linking is a stochastic process resulting from random collisions and support a number of other lines of evidence that lactose permease is a monomer.
BiochemistryLigand Recognition by the Lactose Permease of <i>Escherichia coli</i>: Specificity and Affinity Are Defined by Distinct Structural Elements of Galactopyranosides
45 Citations2000Miklós Sahin‐Tóth, Kauser M. Akhoon +2 more
Both alpha- and beta-methyl D-galactopyranosides bind more strongly than galactose, supporting the notion that the cyclic pyranose conformation is the bound form and that the anomeric configuration at C-1 does not contribute to substrate specificity.
Current Opinion in Chemical BiologyIon channels: doing hard chemistry with hard ions
43 Citations2000Christopher Miller
The recently determined structure of a K(+) channel has put flesh on these bones, revealing the coordination chemistry responsible for the unusual combination of high selectivity and high transport rates in ion channels.
BiochemistryThe C-4 Hydroxyl Group of Galactopyranosides Is the Major Determinant for Ligand Recognition by the Lactose Permease of <i>Escherichia coli</i>
39 Citations2001Miklós Sahin‐Tóth, Mary C. Lawrence +2 more
The results confirm and extend the observations that the C-2,C-3, C-4, and C-6 OH groups of galactopyranosides participate in important H-bonding interactions, suggesting that sugar recognition in lactose permease may have evolved to discriminate primarily between gluco- and galactosyl moiety.
BiochemistryThiol Cross-Linking of Transmembrane Domains IV and V in the Lactose Permease of <i>Escherichia coli</i>
37 Citations2000Christopher D. Wolin, H. Ronald Kaback
It is shown here that Cys residues in place of Glu126 and Arg144, as well as Ala122 and Val149, spontaneously form disulfide bonds in situ, indicating that this region of transmembrane domains IV and V is in the alpha-helical conformation.
Protein ScienceThe role of helix VIII in the lactose permease of <i>Escherichia coli</i>: II. Site‐directed sulfhydryl modification
34 Citations1997Stathis Frillingos, H. Ronald Kaback
The findings indicate that a portion of one face of helix VIII, which is in close proximity to Cys 148 (helix V), interacts with substrate, whereas another position bordering these residues (Thr 265) is altered by a ligand‐induced conformational change.
BiochemistrySite-directed mutagenesis of tyrosine residues in the lac permease of Escherichia coli
28 Citations1989Paul D. Roepe, H. Ronald Kaback
Permease containing Phe in place of Tyr236 catalyzes lactose exchange approximately 40% as well as wild-type permease but does not catalyze active transport or efflux, suggesting that replacement of Tyr382 with Phe alters a kinetic step involving translocation of the unloaded permease across the membrane.
Proceedings of the National Academy of SciencesChanging the lactose permease of <i>Escherichia coli</i> into a galactose-specific symporter
26 Citations2002Lan Guan, Miklós Sahin‐Tóth +1 more
The results demonstrate that Ala-122 is a component of the ligand-binding site and provide a strong indication that the side chain at position 122 abuts on the nongalactosyl moiety of d-galactopyranosides.
Journal of Molecular BiologyManipulating conformational equilibria in the lactose permease of Escherichia coli 1 1Edited by G. von Heijne
22 Citations2002Adam B. Weinglass, Melissa Sondej +1 more
The results suggest that the two classes of mutants rescue activity by altering the equilibrium between outwardly and inwardly facing conformations of the permease such that impaired protonation and/or H(+) transfer is enhanced from one side of the membrane or the other.
BiochemistryFunctional Estimation of Loop−Helix Boundaries in the Lactose Permease of <i>Escherichia coli</i> by Single Amino Acid Deletion Analysis
12 Citations2001Christopher D. Wolin, H. Ronald Kaback
Deletion analysis of loop V/VI, helix VI, and loop VI/VII does not yield an activity profile typical of the rest of the protein, as individual deletion of only three residues in this region abolishes activity, and transmembrane domain VI which is probably on the periphery of the 12-helix bundle may make few functionally important contacts.