Nucleotide sequence analysis of hypervariable junctions of Haemophilus influenzae pilus gene clusters

Related Experiment Video

Updated: Oct 10, 2026

Identification of Novel Genes Associated with Alginate Production in Pseudomonas aeruginosa Using Mini-himar1 Mariner Transposon-mediated Mutagenesis
08:57

Identification of Novel Genes Associated with Alginate Production in Pseudomonas aeruginosa Using Mini-himar1 Mariner Transposon-mediated Mutagenesis

Published on: March 10, 2014

T D Read1, S W Satola, M M Farley

  • 1Atlanta Veterans Affairs Medical Center and Emory University School of Medicine, Atlanta, Georgia, USA.

Infection and Immunity
|November 18, 2000
PubMed

Insights

Haemophilus influenzae pili genes (hifABCDE) show distinct genomic insertion patterns. The hif-2 junctions are complex and variable, unlike the simpler hif-1, suggesting different evolutionary paths for these pathogenicity islands.

Area of Science:

  • Microbiology
  • Genomics
  • Molecular Biology

Background:

  • Haemophilus influenzae utilizes pili for attachment to human epithelial cells.
  • The genes encoding pili (hifABCDE) are located in two distinct genomic positions: hif-1 and hif-2.

Purpose of the Study:

  • To analyze the genomic sequences surrounding the pilus gene clusters (hif-1 and hif-2) in H. influenzae.
  • To understand the structural variations and evolutionary origins of these pilus gene clusters.

Main Methods:

  • DNA sequencing of intergenic regions and flanking genes in various H. influenzae strains.
  • Comparative genomic analysis of hif-1 and hif-2 cluster junctions.

Main Results:

  • hif-1 junctions, found in biogroup aegyptius, are structurally simple.
  • hif-2 junctions exhibit high diversity, characterized by complex assemblies of intergenic sequences (including hicA and hicB) and frequent recombination.
  • Variation in hif-2 junctions is associated with multiple copies of a 23-bp Haemophilus intergenic dyad sequence.
  • The hif-1 cluster likely arose from hif-2 genes within the hpt-pmbA region.

Conclusions:

  • The hif-2 pilus gene cluster represents a highly dynamic and recombinogenic mobile genetic element.
  • The hif-1 cluster's origin in biogroup aegyptius involves a specific integration event of hif-2 related DNA.
  • Pilus gene clusters in H. influenzae serve as a model for pathogenicity islands independent of typical mobile genetic elements like phages or transposons.

More Related Videos

Bidirectional Retroviral Integration Site PCR Methodology and Quantitative Data Analysis Workflow12:53

Bidirectional Retroviral Integration Site PCR Methodology and Quantitative Data Analysis Workflow

Published on: June 14, 2017

Long-Read Plasmid Sequencing and Assembly Using Nanopore Sequencing-Based Workflows10:27

Long-Read Plasmid Sequencing and Assembly Using Nanopore Sequencing-Based Workflows

Published on: July 7, 2026

Related Concept Videos

Fimbriae, Pili, and Axial Filaments01:28

Fimbriae, Pili, and Axial Filaments

Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
DNA Bacteriophages01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
Genomic DNA in Prokaryotes00:46

Genomic DNA in Prokaryotes

The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...