Publications by authors named "D Perkins-Balding"

The use of recombinases for genomic engineering is no longer a new technology. In fact, this technology has entered its third decade since the initial discovery that recombinases function in heterologous systems (Sauer in Mol Cell Biol 7(6):2087-2096, 1987). The random insertion of a transgene into a plant genome by traditional methods generates unpredictable expression patterns.

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Several genetic systems that allow the use of iron-protoporphyrin IX (heme) have been described for the pathogenic bacterium Neisseria meningitidis. However, many questions about the process of heme acquisition and utilization remain to be answered. To isolate and analyze unidentified genes that play a role in heme iron uptake and utilization, a Himar1 transposon mutant library was screened in N.

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Neisseria gonorrhoeae (the gonococcus) is an obligate human pathogen and the causative agent of the disease gonorrhea. The gonococcal pilus undergoes antigenic variation through high-frequency recombination events between unexpressed pilS silent copies and the pilin expression locus pilE. The machinery involved in pilin antigenic variation identified to date is composed primarily of genes involved in homologous recombination.

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Acquisition of iron and iron complexes has long been recognized as a major determinant in the pathogenesis of Neisseria meningitidis. In this review, high-affinity iron uptake systems, which allow meningococci to utilize the human host proteins transferrin, lactoferrin, hemoglobin, and haptoglobin-hemoglobin as sources of essential iron, are described. Classic features of bacterial iron transport systems, such as regulation by the iron-responsive repressor Fur and TonB-dependent transport activity, are discussed, as well as more specific features of meningococcal iron transport.

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The HmbR outer-membrane receptor enables Neisseria meningitidis to use haemoglobin (Hb) as a source of iron. This protein functions by binding Hb, removing haem from it, and releasing the haem into the periplasm. Functionally important HmbR receptor domains were discerned using a series of HmbR deletions and site-directed mutations.

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