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F Pagotto

Publications and source records attributed to F Pagotto.

8 recordsLinked to original sources
PubMed2002

Integration host factor interactions with Neisseria gene sequences: correlation between predicted binding sites and in vitro binding of Neisseria -derived IHF protein.

Putative integration host factor (IHF) binding sites are frequently being identified in Neisseria gene sequences on the basis of similarity to a degenerate Escherichia coli -derived consensus binding sequence. In this report, three different Neisseria genetic systems that contain predicted IHF binding sites were assessed for IHF binding through gel retardation analysis. The results show a positive correlation between the identification of a predicted Neisseria IHF binding site and in vitro binding of Neisseria -derived IHF protein.

Base Sequence↗
PubMed2001

Multiple origins and replication proteins influence biological properties of beta-lactamase-producing plasmids from Neisseria gonorrhoeae.

The beta-lactamase-producing Asia-type plasmid pJD4 of Neisseria gonorrhoeae is a 7.4-kb, broad-host-range plasmid. It is part of a family of plasmids which are structurally related yet vary in size, found in both N. gonorrhoeae and Haemophilus ducreyi. Branch-point analysis by electron microscopy indicates that pJD4 carries three clustered but distinguishable origins of replication, which we named ori1, ori2, and ori3. Although pJD4 belongs to incompatibility (Inc) group W, it also carries a silent IncFII determinant which is expressed when ori2 and ori3 are absent. The Africa-type plasmid pJD5, a naturally occurring deletion derivative of pJD4, carries only ori1, belongs to the IncFII group, and, in contrast to pJD4, requires DNA polymerase I (Pol I) for replication. Plasmids constructed from pJD4 which lack ori1 but carry ori2 and ori3 do not require Pol I and are incompatible with IncW plasmids, suggesting that the ori2 or ori3 region contains the IncW determinant. We have cloned a replication initiation protein (RepB) that is necessary for ori2 and ori3 to function. This Rep protein is distinct from RepA, which is necessary for ori1. Thus, pJD4 is unique because it is the smallest plasmid characterized containing three origins of replication and two unique Rep proteins.

Bacterial Proteins↗
PubMed2000

Sequence analysis of the family of penicillinase-producing plasmids of Neisseria gonorrhoeae.

The exact nature of the sequence differences between the medically important family of gonococcal penicillinase-producing plasmids has been ascertained. The entire DNA sequence of the Asia-type plasmid, pJD4, demonstrated that it is 7426 bp and contains two direct repeats (DR30) that are implicated in the formation of deletion variant plasmids, such as the Africa-type plasmid. We have identified putative DnaA and IHF binding sites, various open reading frames that are thought to specify functional proteins, and some important DNA sequences involved with conjugative transfer of gonococcal beta-lactamase plasmids. The deletion in the Africa-type plasmid is 1827 bp and one of the DR30 repeats is also missing. The deletion in the Rio-type plasmid and several Toronto-type plasmids was determined to be 2273 bp and the sequence spanning the deletion was identical irrespective of geographic or temporal origin. The &Ncirc;imes-type plasmid is an Africa-type plasmid and also contains an IS5 insertion sequence. Since IS5 has not been identified in gonococcal isolates, we suggest that this sequence may have been inserted after the original gonococcal plasmid was transformed into Escherichia coli. The New Zealand plasmid is an Asia-type plasmid that contains an endogenous tandem duplication of 1883 bp and the direct DR2 is implicated in this duplication. The nature of the defined truncation of Tn2 present in the various plasmids is also discussed.

Base Sequence↗
PubMed1995

The inhibitory properties of various sponges on Listeria spp.

Various retail and environmental sponges were tested for inhibitory properties against Listeria species and several other bacterial genera. Sterile sponges, unrinsed and rinsed in sterile distilled water or sterile neutralizing buffer, were placed on seeded plates of tryptic soy agar with 0.6% yeast extract. Plates were incubated at 30 degrees C for 24 h and zones of inhibition measured. The Systems Plus environmental sponge and the Technical Service Consultants Ltd sponge (sTc) proved to be the only sponges which consistently demonstrated no inhibitory properties. Results using scanning electron microscopy showed considerable bacterial attachment to the Systems Plus sponge, further corroborating these findings.

Disinfection↗