Lactose repressor hinge domain independently binds DNA

Simple item page
dc.citation.firstpage839en_US
dc.citation.issueNumber4en_US
dc.citation.journalTitleProtein Scienceen_US
dc.citation.lastpage847en_US
dc.citation.volumeNumber27en_US
dc.contributor.authorXu, Joseph S.en_US
dc.contributor.authorHewitt, Madeleine N.en_US
dc.contributor.authorGulati, Jaskeerat S.en_US
dc.contributor.authorCruz, Matthew A.en_US
dc.contributor.authorZhan, Honglien_US
dc.contributor.authorLiu, Shirleyen_US
dc.contributor.authorMatthews, Kathleen S.en_US
dc.date.accessioned2018-07-11T20:57:33Zen_US
dc.date.available2018-07-11T20:57:33Zen_US
dc.date.issued2018en_US
dc.description.abstractThe short 8–10 amino acid “hinge” sequence in lactose repressor (LacI), present in other LacI/GalR family members, links DNA and inducer‐binding domains. Structural studies of full‐length or truncated LacI‐operator DNA complexes demonstrate insertion of the dimeric helical “hinge” structure at the center of the operator sequence. This association bends the DNA ∼40° and aligns flanking semi-symmetric DNA sites for optimal contact by the N-terminal helix-turn-helix (HtH) sequences within each dimer. In contrast, the hinge region remains unfolded when bound to nonspecific DNA sequences. To determine ability of the hinge helix alone to mediate DNA binding, we examined (i) binding of LacI variants with deletion of residues 1–50 to remove the HtH DNA binding domain or residues 1–58 to remove both HtH and hinge domains and (ii) binding of a synthetic peptide corresponding to the hinge sequence with a Val52Cys substitution that allows reversible dimer formation via a disulfide linkage. Binding affinity for DNA is orders of magnitude lower in the absence of the helix‐turn‐helix domain with its highly positive charge. LacI missing residues 1–50 binds to DNA with ∼4-fold greater affinity for operator than for nonspecific sequences with minimal impact of inducer presence; in contrast, LacI missing residues 1–58 exhibits no detectable affinity for DNA. In oxidized form, the dimeric hinge peptide alone binds to O1 and nonspecific DNA with similarly small difference in affinity; reduction to monomer diminished binding to both O1 and nonspecific targets. These results comport with recent reports regarding LacI hinge interaction with DNA sequences.en_US
dc.identifier.citationXu, Joseph S., Hewitt, Madeleine N., Gulati, Jaskeerat S., et al.. "Lactose repressor hinge domain independently binds DNA." <i>Protein Science,</i> 27, no. 4 (2018) Wiley: 839-847. https://doi.org/10.1002/pro.3372.en_US
dc.identifier.doihttps://doi.org/10.1002/pro.3372en_US
dc.identifier.urihttps://hdl.handle.net/1911/102407en_US
dc.language.isoengen_US
dc.publisherWileyen_US
dc.rightsThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.en_US
dc.rights.urihttps://creativecommons.org/licenses/by-nc/4.0/en_US
dc.subject.keywordallosteric regulationen_US
dc.subject.keywordDNA binding proteinen_US
dc.subject.keywordDNA operatoren_US
dc.subject.keywordDNA–protein interactionen_US
dc.subject.keywordhinge helixen_US
dc.subject.keywordlactose repressor proteinen_US
dc.subject.keywordstructure–functionen_US
dc.titleLactose repressor hinge domain independently binds DNAen_US
dc.typeJournal articleen_US
dc.type.dcmiTexten_US
dc.type.publicationpublisher versionen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Xu_et_al-2018.pdf
Size:
406.15 KB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Faculty Publications
BioSciences Publications