Biomaterial Database

Molecular nature of two beta-lactamase-specifying plasmids isolated from Haemophilus influenzae type b. 1976

J De Graaff, and L P Elwell, and S Falkow

The molecular nature of two beta-lactamase-specifying plasmids isolated from two separate ampicillin-resistant Haemophilus influenzae type b strains was examined. A 30 X 10(6)-dalton (30-Mdal) plasmid (RSF007) had a copy number of approximately 3 per chromosomal equivalent and a mole fraction guanine plus cytosine content of 0.39. By heteroduplex analysis the 30-Mdal plasmid was found to contain the entire ampicillin translocation DNA segment (TnA) found on R factors of enteric origin. A 3.0-Mdal plasmid (RSF0885) was found as a multicopy pool of approximately 28 copies per chromosomal equivalent, had a mole fraction guanine plus cytosine content of 0.40, and contained only about one-third of the transposable TnA sequence. RSF007 and RSF0885 appeared to be unrelated plasmids in that they share base sequence homology only within the confines of the TnA segment. The 3.0-Mdal Haemophilus plasmid was used to transform E. coli to ampicillin resistance but was found to be unstable in this host in the absence of antibiotic. The possibility that R-plasmids arose in Haemophilus by the translocation of TnA from a donor R-factor onto an indigenous H. influenzae plasmid is discussed.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D010403	Penicillin Resistance	Nonsusceptibility of an organism to the action of penicillins.	Penicillin Resistances,Resistance, Penicillin,Resistances, Penicillin
D010405	Penicillinase	A beta-lactamase preferentially cleaving penicillins. (Dorland, 28th ed) EC 3.5.2.-.	beta-Lactamase I,AER-I beta-Lactamase,Benzylpenicillinase,Carbenicillinase,Exopenicillinase,beta Lactamase III,beta Lactamase RP4,gamma-Penicillinase,AER I beta Lactamase,Lactamase RP4, beta,beta Lactamase I,beta-Lactamase, AER-I,gamma Penicillinase
D011815	R Factors	A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.	R Factor,R Plasmid,R Plasmids,Resistance Factor,Resistance Factors,Factor, R,Factor, Resistance,Factors, R,Factors, Resistance,Plasmid, R,Plasmids, R
D002876	Chromosomes, Bacterial	Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.	Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA