lacY lactose permease [Escherichia coli str. K-12 substr. MG1655] - Gene

Summary

Go to the top of the page Help

Gene symbol: lacY
Gene description: lactose permease
Primary source: ASAP:ABE-0001181
Locus tag: b0343
See related: ECOCYC:EG10526
Gene type: protein coding
RefSeq status: PROVISIONAL
Organism: Escherichia coli str. K-12 substr. MG1655 (strain: K-12, substrain: MG1655)
Lineage: Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia
Also known as: ECK0340
Summary: Major Facilitator Superfamily (MFS). [More information is available at EcoGene: EG10526]. The lactose permease LacY is a lactose/proton symporter, responsible for the uptake of lactose and other galactosides. [More information is available at EcoCyc: EG10526].
NEW: Try the new Gene table
Try the new Transcript table

Genomic context

Go to the top of the page Help

Sequence:: NC_000913.3 (361926..363179, complement)

NC_000913.3 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

Go to the top of the page Help

Go to reference sequence details

Genomic Sequence:: NC_000913.3

Go to nucleotide: Graphics FASTA GenBank

Bibliography

Go to the top of the page Help

GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Structural and Functional Adaptability of Sucrose and Lactose Permeases from Escherichia coli to the Membrane Lipid Composition.
Title: Structural and Functional Adaptability of Sucrose and Lactose Permeases from Escherichia coli to the Membrane Lipid Composition.
Diversity in kinetics correlated with structure in nano body-stabilized LacY.
Title: Diversity in kinetics correlated with structure in nano body-stabilized LacY.
Binding kinetics of alpha-galactopyranoside homologs with fluorescent aglycones of different sizes or shapes were determined with Escherichia coli LacY by FRET from Trp151 in the LacY binding site to the fluorophores. LacY specificity is directed toward the galactopyranoside ring. The pathway for the substrate entering from the periplasmic side is wider than the calculated pore diameters in periplasmic open X-ray struc...
Title: Oversized galactosides as a probe for conformational dynamics in LacY.
Glu325 exhibits a pKa of 10.5 +/- 0.1 that is insensitive to the presence of galactopyranoside. Protonation of Glu325 specifically is required for effective sugar binding to LacY
Title: pK(a) of Glu325 in LacY.
Data indicate that the nanobodies (Nbs) bind stoichiometrically with nanomolar affinity to the periplasmic face of lactose permease (LacY) primarily to the C-terminal six-helix bundle.
Title: Crystal structure of a LacY-nanobody complex in a periplasmic-open conformation.
studies suggest that a single carboxyl group in LacY (Glu325) may be the only side chain directly involved in H+ translocation and a carboxyl side chain with similar properties has been identified in FucP (Asp46) and XylE (Asp27), the present results imply that the pK of this residue is switched during H+/sugar symport in all three symporters.
Title: pH Regulation of Electrogenic Sugar/H+ Symport in MFS Sugar Permeases.
Molecular dynamics simulations indicated that the deprotonation of Glu325 induced the opening of the periplasmics side and partial closure of the cytoplasmic side of LacY, while protonation of the Glu269 caused a stable cross-domain salt-bridge (Glu130-Arg344) and completely closed the cytoplasmic side.
Title: Coarse-grained simulations of proton-dependent conformational changes in lactose permease.
The YidC prevents LacY from misfolding by stabilizing the unfolded state from which LacY inserts structural segments stepwise into the membrane until folding is completed. During stepwise insertion, YidC and the membrane together stabilize the transient folds.
Title: YidC assists the stepwise and stochastic folding of membrane proteins.
Double-replacement mutants of conserved Gly-Gly pairs bind galactoside with affinities 10-20-fold higher than that of the pseudo-WT or WT LacY. Moreover, site-directed alkylation of a periplasmic Cys replacement indicates that the periplasmic cavity becomes readily accessible in the double-replacement mutants.
Title: Role of Conserved Gly-Gly Pairs on the Periplasmic Side of LacY.
Studied conformational states and homology of LacY and XylE.
Title: Conserved movement of TMS11 between occluded conformations of LacY and XylE of the major facilitator superfamily suggests a similar hinge-like mechanism.

Submit: New GeneRIF Correction See all GeneRIFs (46)

General gene information

Go to the top of the page Help

Gene Ontology Provided by EcoCyc

Function	Evidence Code	Pubs
enables carbohydrate:proton symporter activity	IDA Inferred from Direct Assay more info	PubMed
enables carbohydrate:proton symporter activity	IEA Inferred from Electronic Annotation more info
enables lactose binding	IBA Inferred from Biological aspect of Ancestor more info
enables lactose binding	IDA Inferred from Direct Assay more info	PubMed
enables lactose:proton symporter activity	IBA Inferred from Biological aspect of Ancestor more info
enables lactose:proton symporter activity	IDA Inferred from Direct Assay more info	PubMed
enables lactose:proton symporter activity	IMP Inferred from Mutant Phenotype more info	PubMed
enables protein binding	IPI Inferred from Physical Interaction more info	PubMed
enables symporter activity	IEA Inferred from Electronic Annotation more info
enables transmembrane transporter activity	IEA Inferred from Electronic Annotation more info

Process	Evidence Code	Pubs
involved_in carbohydrate transmembrane transport	IEA Inferred from Electronic Annotation more info
involved_in carbohydrate transport	IEA Inferred from Electronic Annotation more info
acts_upstream_of_or_within carbohydrate transport	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in carbohydrate transport	IMP Inferred from Mutant Phenotype more info	PubMed
acts_upstream_of_or_within lactose transport	IDA Inferred from Direct Assay more info	PubMed
involved_in organic substance transport	IBA Inferred from Biological aspect of Ancestor more info
involved_in organic substance transport	IEA Inferred from Electronic Annotation more info
involved_in proton transmembrane transport	IEA Inferred from Electronic Annotation more info
involved_in transmembrane transport	IEA Inferred from Electronic Annotation more info

Component	Evidence Code	Pubs
located_in membrane	IDA Inferred from Direct Assay more info	PubMed
located_in membrane	IEA Inferred from Electronic Annotation more info
is_active_in plasma membrane	IBA Inferred from Biological aspect of Ancestor more info
located_in plasma membrane	IDA Inferred from Direct Assay more info	PubMed
located_in plasma membrane	IEA Inferred from Electronic Annotation more info

General protein information

Go to the top of the page Help

Preferred Names: lactose permease

NCBI Reference Sequences (RefSeq)

Go to the top of the page Help

NEW Try the new Transcript table

Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

NC_000913.3 Reference assembly

Range

361926..363179 complement

Download

GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NP_414877.1 lactose permease [Escherichia coli str. K-12 substr. MG1655]

See identical proteins and their annotated locations for NP_414877.1

Status: PROVISIONAL

UniProtKB/TrEMBL

A0A5B9AUY1

Conserved Domains (1) summary

pfam01306
Location:1 → 413

LacY_symp; LacY proton/sugar symporter