lacI DNA-binding transcriptional repressor LacI [Escherichia coli str. K-12 substr. MG1655] - Gene

Summary

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Official Symbol: lacI
Official Full Name: DNA-binding transcriptional repressor LacI
Primary source: ECOCYC:EG10525
Locus tag: b0345
See related: ASAP:ABE-0001189
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: ECK0342
Summary: The Lactose inhibitor," LacI, is a DNA-binding transcription factor that represses transcription of the operon involved in transport and catabolism of lactose . [More information is available at EcoCyc: EG10525].
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Genomic context

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Sequence:: NC_000913.3 (366428..367510, complement)

NC_000913.3 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:: NC_000913.3

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Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Rheostat functional outcomes occur when substitutions are introduced at nonconserved positions that diverge with speciation.
Title: Rheostat functional outcomes occur when substitutions are introduced at nonconserved positions that diverge with speciation.
Effect of helix length on the stability of the Lac repressor antiparallel coiled coil.
Title: Effect of helix length on the stability of the Lac repressor antiparallel coiled coil.
LacI autoregulation balances two opposing states, one that allows quicker response to smaller pulses of external lactose, and the other that minimizes production costs in the absence of lactose.
Title: The effect of LacI autoregulation on the performance of the lactose utilization system in Escherichia coli.
Data indicate that in the absence of its inducer, LacI binds to primary operator lac O1 near the transcription start site of the lac operon, and represses its transcription.
Title: Exploring the sequence-function relationship in transcriptional regulation by the lac O1 operator.
findings show the lac repressor slides 45 +/- 10 base pairs on chromosomal DNA and that sliding can be obstructed by other DNA-bound proteins near the operator; the repressor frequently slides over its natural lacO(1) operator several times before binding
Title: The lac repressor displays facilitated diffusion in living cells.
The role of lactose repressor residues asparagine-125 and aspartate-149 illustrate how readily the ligand binding and allosteric response function of a regulatory bacterial protein can be altered, generating diminished operator binding.
Title: Altering residues N125 and D149 impacts sugar effector binding and allosteric parameters in Escherichia coli lactose repressor.
Using the extensive LacI family of transcriptional factors, identified a set of specificity correlations--determined by two AAs of the TFs and two NTs in the binding sites- and that act as a relatively consistent recognition code.
Title: Local gene regulation details a recognition code within the LacI transcriptional factor family.
The structure of lactose repressor (LacI) protein confirms previously reported structures on the monomer level, however, the tetramer is much more densely packed.
Title: Crystal structure of a 1.6-hexanediol bound tetrameric form of Escherichia coli lac-repressor refined to 2.1 A resolution.
irradiation induces the change of the oligomerization state of LacI from tetramer to dimer.
Title: Radiation-induced tetramer-to-dimer transition of Escherichia coli lactose repressor.
N-terminus verified by Edman degradation on complete protein
Title: Lac repressor. Specific proteolytic destruction of the NH 2 -terminal region and loss of the deoxyribonucleic acid-binding activity.

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Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Homology

Orthologs from OrthoDB

Gene Ontology Provided by EcoCyc

Function	Evidence Code	Pubs
enables DNA binding	IEA Inferred from Electronic Annotation more info
enables DNA-binding transcription factor activity	IBA Inferred from Biological aspect of Ancestor more info
enables DNA-binding transcription repressor activity	IDA Inferred from Direct Assay more info	PubMed
enables cis-regulatory region sequence-specific DNA binding	IDA Inferred from Direct Assay more info	PubMed
enables identical protein binding	IPI Inferred from Physical Interaction more info	PubMed
enables transcription cis-regulatory region binding	IBA Inferred from Biological aspect of Ancestor more info

Process	Evidence Code	Pubs
acts_upstream_of_or_within negative regulation of DNA-templated transcription	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in regulation of DNA-templated transcription	IBA Inferred from Biological aspect of Ancestor more info
involved_in regulation of DNA-templated transcription	IEA Inferred from Electronic Annotation more info

Component	Evidence Code	Pubs
located_in cytosol	HDA more info	PubMed

General protein information

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Preferred Names: DNA-binding transcriptional repressor LacI

NCBI Reference Sequences (RefSeq)

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Genome Annotation

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Reference assembly

Genomic

NC_000913.3 Reference assembly

Range

366428..367510 complement

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NP_414879.3 DNA-binding transcriptional repressor LacI [Escherichia coli str. K-12 substr. MG1655]

See identical proteins and their annotated locations for NP_414879.3

Status: PROVISIONAL

UniProtKB/TrEMBL

A0A5C9AMJ5, A0A7H9NJ06

Conserved Domains (1) summary

PRK09526
Location:1 → 340

lacI; lac repressor; Reviewed