The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in helicobacter pylori

Oscar Almarza, Daniel Núñez, Hector Toledo

Resultado de la investigación: Article

8 Citas (Scopus)

Resumen

Bacterial genomes are compacted by association with histone-like proteins to form a complex known as bacterial chromatin. The histone-like protein HU is capable of binding and bending the DNA molecule, a function related to compaction, protection, and regulation of gene expression. In Helicobacter pylori, HU is the only histone-like protein described so far. Proteomic analysis from our laboratory showed that this protein is overexpressed under acidic stress. Materials and Methods: We used a purified recombinant wild-type protein and two mutant proteins with the amino acid substitutions K3A/S27D and K62R/V63N/P64A to characterize the function of the N-terminal domain and the flexible arm of HU. Results: In vitro assays for DNA protection, bending, and compaction were performed. We also designed a H. pylori hup::cat mutant strain to study the role of HU in the acid stress response. HUwt protein binds DNA and promotes its bending and compaction. Compared with the wild-type protein, both mutant proteins have less affinity for DNA and an impaired bending and compaction ability. By using qRT-PCR, we confirmed overexpression of two genes related to acid stress response (ureA and speA). Such overexpression was abolished in the hup::cat strain, which shows an acid-sensitive phenotype. Conclusions: Altogether, we have shown that HUwt-DNA complex formation is favored under acidic pH and that the complex protects DNA from endonucleolytic cleavage and oxidative stress damage. We also showed that the amino-terminal domain of HU is relevant to DNA-protein complex formation and that the flexible arm of HU is involved in the bending and compaction activities of HU.

Idioma originalEnglish
Páginas (desde-hasta)29-40
Número de páginas12
PublicaciónHelicobacter
Volumen20
N.º1
DOI
EstadoPublished - 1 feb 2015

Huella dactilar

DNA-Binding Proteins
Helicobacter pylori
Acids
DNA
Proteins
Histones
Mutant Proteins
Cats
Bacterial Genomes
DNA Cleavage
Gene Expression Regulation
Amino Acid Substitution
Recombinant Proteins
Proteomics
Chromatin
Urea
Oxidative Stress
Phenotype
Polymerase Chain Reaction
Genes

ASJC Scopus subject areas

  • Gastroenterology
  • Infectious Diseases
  • Medicine(all)

Citar esto

Almarza, Oscar ; Núñez, Daniel ; Toledo, Hector. / The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in helicobacter pylori. En: Helicobacter. 2015 ; Vol. 20, N.º 1. pp. 29-40.
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title = "The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in helicobacter pylori",
abstract = "Bacterial genomes are compacted by association with histone-like proteins to form a complex known as bacterial chromatin. The histone-like protein HU is capable of binding and bending the DNA molecule, a function related to compaction, protection, and regulation of gene expression. In Helicobacter pylori, HU is the only histone-like protein described so far. Proteomic analysis from our laboratory showed that this protein is overexpressed under acidic stress. Materials and Methods: We used a purified recombinant wild-type protein and two mutant proteins with the amino acid substitutions K3A/S27D and K62R/V63N/P64A to characterize the function of the N-terminal domain and the flexible arm of HU. Results: In vitro assays for DNA protection, bending, and compaction were performed. We also designed a H. pylori hup::cat mutant strain to study the role of HU in the acid stress response. HUwt protein binds DNA and promotes its bending and compaction. Compared with the wild-type protein, both mutant proteins have less affinity for DNA and an impaired bending and compaction ability. By using qRT-PCR, we confirmed overexpression of two genes related to acid stress response (ureA and speA). Such overexpression was abolished in the hup::cat strain, which shows an acid-sensitive phenotype. Conclusions: Altogether, we have shown that HUwt-DNA complex formation is favored under acidic pH and that the complex protects DNA from endonucleolytic cleavage and oxidative stress damage. We also showed that the amino-terminal domain of HU is relevant to DNA-protein complex formation and that the flexible arm of HU is involved in the bending and compaction activities of HU.",
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The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in helicobacter pylori. / Almarza, Oscar; Núñez, Daniel; Toledo, Hector.

En: Helicobacter, Vol. 20, N.º 1, 01.02.2015, p. 29-40.

Resultado de la investigación: Article

TY - JOUR

T1 - The DNA-binding protein HU has a regulatory role in the acid stress response mechanism in helicobacter pylori

AU - Almarza, Oscar

AU - Núñez, Daniel

AU - Toledo, Hector

PY - 2015/2/1

Y1 - 2015/2/1

N2 - Bacterial genomes are compacted by association with histone-like proteins to form a complex known as bacterial chromatin. The histone-like protein HU is capable of binding and bending the DNA molecule, a function related to compaction, protection, and regulation of gene expression. In Helicobacter pylori, HU is the only histone-like protein described so far. Proteomic analysis from our laboratory showed that this protein is overexpressed under acidic stress. Materials and Methods: We used a purified recombinant wild-type protein and two mutant proteins with the amino acid substitutions K3A/S27D and K62R/V63N/P64A to characterize the function of the N-terminal domain and the flexible arm of HU. Results: In vitro assays for DNA protection, bending, and compaction were performed. We also designed a H. pylori hup::cat mutant strain to study the role of HU in the acid stress response. HUwt protein binds DNA and promotes its bending and compaction. Compared with the wild-type protein, both mutant proteins have less affinity for DNA and an impaired bending and compaction ability. By using qRT-PCR, we confirmed overexpression of two genes related to acid stress response (ureA and speA). Such overexpression was abolished in the hup::cat strain, which shows an acid-sensitive phenotype. Conclusions: Altogether, we have shown that HUwt-DNA complex formation is favored under acidic pH and that the complex protects DNA from endonucleolytic cleavage and oxidative stress damage. We also showed that the amino-terminal domain of HU is relevant to DNA-protein complex formation and that the flexible arm of HU is involved in the bending and compaction activities of HU.

AB - Bacterial genomes are compacted by association with histone-like proteins to form a complex known as bacterial chromatin. The histone-like protein HU is capable of binding and bending the DNA molecule, a function related to compaction, protection, and regulation of gene expression. In Helicobacter pylori, HU is the only histone-like protein described so far. Proteomic analysis from our laboratory showed that this protein is overexpressed under acidic stress. Materials and Methods: We used a purified recombinant wild-type protein and two mutant proteins with the amino acid substitutions K3A/S27D and K62R/V63N/P64A to characterize the function of the N-terminal domain and the flexible arm of HU. Results: In vitro assays for DNA protection, bending, and compaction were performed. We also designed a H. pylori hup::cat mutant strain to study the role of HU in the acid stress response. HUwt protein binds DNA and promotes its bending and compaction. Compared with the wild-type protein, both mutant proteins have less affinity for DNA and an impaired bending and compaction ability. By using qRT-PCR, we confirmed overexpression of two genes related to acid stress response (ureA and speA). Such overexpression was abolished in the hup::cat strain, which shows an acid-sensitive phenotype. Conclusions: Altogether, we have shown that HUwt-DNA complex formation is favored under acidic pH and that the complex protects DNA from endonucleolytic cleavage and oxidative stress damage. We also showed that the amino-terminal domain of HU is relevant to DNA-protein complex formation and that the flexible arm of HU is involved in the bending and compaction activities of HU.

KW - Acidic condition

KW - DNA

KW - DNA damage

KW - Protein

KW - Proteome

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U2 - 10.1111/hel.12171

DO - 10.1111/hel.12171

M3 - Article

C2 - 25256909

AN - SCOPUS:84920825176

VL - 20

SP - 29

EP - 40

JO - Helicobacter

JF - Helicobacter

SN - 1083-4389

IS - 1

ER -