ArticleJournal of molecular biology2010
Helix dynamics in LacY: helices II and IV.
Article in Journal of molecular biology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
12 citing papers in PubMed, 25 citations in OpenAlex.
- Lactose Permease Scrambles Phospholipids.Biology · 2023Article
- Substitutions that lock and unlock the proton-coupled folate transporter (PCFT-SLC46A1) in an inward-open conformation.The Journal of biological chemistry · 2019Article
- Protonation drives the conformational switch in the multidrug transporter LmrP.Nature chemical biology · 2014Article
- Evolutionary mix-and-match with MFS transporters II.Proceedings of the National Academy of Sciences of the United States of America · 2013Article
- Structure of the YajR transporter suggests a transport mechanism based on the conserved motif A.Proceedings of the National Academy of Sciences of the United States of America · 2013Article
- Evolutionary mix-and-match with MFS transporters.Proceedings of the National Academy of Sciences of the United States of America · 2013Article
- Proton-coupled dynamics in lactose permease.Structure (London, England : 1993) · 2012Article
- Apo-intermediate in the transport cycle of lactose permease (LacY).Proceedings of the National Academy of Sciences of the United States of America · 2012Article
- Lactose permease and the alternating access mechanism.Biochemistry · 2011Article
- The alternating access transport mechanism in LacY.The Journal of membrane biology · 2011Review
- Using student-generated UV-induced Escherichia coli mutants in a directed inquiry undergraduate genetics laboratory.Genetics · 2010Article
- Sugar binding induces the same global conformational change in purified LacY as in the native bacterial membrane.Proceedings of the National Academy of Sciences of the United States of America · 2010Article
Corrections and comments
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
Biochemical and biophysical studies based upon crystal structures of both a mutant and wild-type lactose permease from Escherichia coli (LacY) in an inward-facing conformation have led to a model for the symport mechanism in which both sugar and H+ binding sites are alternatively accessible to both sides of the membrane. Previous findings indicate that the face of helix II with Asp68 is important for the conformational changes that occur during turnover. As shown here, replacement of Asp68 at the cytoplasmic end of helix II, particularly with Glu, abolishes active transport but the mutants retain the ability to bind galactopyranoside. In the x-ray structure, Asp68 and Lys131 (helix IV) lie within approximately 4.2 A of each other. Although a double mutant with Cys replacements at both position 68 and position 131 cross-links efficiently, single replacements for Lys131 exhibit very significant transport activity. Site-directed alkylation studies show that sugar binding by the Asp68 mutants causes closure of the cytoplasmic cavity, similar to wild-type LacY; however, strikingly, the probability of opening the periplasmic pathway upon sugar binding is markedly reduced. Taken together with results from previous mutagenesis and cross-linking studies, these findings lead to a model in which replacement of Asp68 blocks a conformational transition involving helices II and IV that is important for opening the periplasmic cavity. Evidence suggesting that movements of helices II and IV are coupled functionally with movements in the pseudo-symmetrically paired helices VIII and X is also presented.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.