Record Details

Newly-discovered behaviour in the bacterial histone-like protein, HU

NOPR - NISCAIR Online Periodicals Repository

View Archive Info
 
 
Field Value
 
Title Newly-discovered behaviour in the bacterial histone-like protein, HU
 
Creator Gupta, Archit
Thakur, Bhishem
Arora, Kanika
Guptasarma, Purnananda
 
Subject Biofilms
DNA compaction
DNA condensation
DNA-binding protein
Histone-like protein
HU
Leaky gene expression
Liquid-liquid phase separation
Nucleoid associated proteins (NAPs)
Protein engineering
Protein evolution
Tryptophan photooxidation
 
Description 666-672
This paper summarizes the contents of a talk delivered at the MS University of Baroda (Vadodara, Gujarat) on 3rd March,
2023, at a conference held to celebrate proteins in commemoration of the birth centenary of Prof. G. N. Ramachandran. Here,
we review several recent discoveries and applications from our group that relate to HU, a DNA-binding nucleoid-associated
protein found in bacteria: (1) HU uses its DNA-binding sites to bind to lipopolysaccharide (LPS) upon bacterial cell surfaces, in
the extracellular milieu in biofilms, thus working as a glue to attach bacteria to extracellular DNA; (2) HU and DNA perform
mutual macromolecular crowding, as well as mutual charge neutralization, to together undergo condensation into nucleoids that
appear to maintain DNA in a compacted state in bacterial genomes through liquid-liquid phase separation (LLPS); (3) HU
appears to have evolved to avoid use of the amino acid residue, tryptophan, to avoid damage to bacterial genomic DNA by a
combination of sunlight and photosensitized oxidation by tryptophan photodecomposition products; (4) HU’s N-terminal
(positive) charge destabilizes hydrophobic inter-subunit interactions between beta strands in HU dimers and promotes subunit
exchange between HU-A and HU-B (the two isoforms of HU in gut bacteria), thus hindering the facile dissociation of subunits
if an N-terminal 6xHis affinity tag is present; (5) HU-A and HU-B can be genetically fused to generate a simulacrum of an HU
heterodimer; (6) HU’s DNA-binding regions from two bacterial homologs (one mesophilic and the other thermophilic) can be
isolated and genetically fused to generate a novel thermostable DNA-binding protein; (7) HU’s ability to titrate onto the
bacterium’s nucleoid can be exploited to deploy fluorescent protein-labelled HU in cells to test for leaky expression from
bacterial promoters, using fluorescence microscopy.
 
Date 2023-09-20T05:22:51Z
2023-09-20T05:22:51Z
2023-09
 
Type Article
 
Identifier 0975-0959 (Online); 0301-1208 (Print)
http://nopr.niscpr.res.in/handle/123456789/62536
https://doi.org/10.56042/ijbb.v60i9.4572
 
Language en
 
Publisher NIScPR-CSIR,India
 
Source IJBB Vol.60(09) [September 2023]