Size and physical map of the chromosome of Haemophilus influenzae.
A variation of pulse-field electrophoresis, field-inversion gel electrophoresis, was used to determine the size and physical map of the chromosome of Haemophilus influenzae. The DNA of H. influenzae had a low G + C content (39%) and no restriction sites for the enzymes NotI or SfiI. However, a number of restriction enzymes (SmaI, ApaI, NaeI, and SacII) that recognized 6-base-pair sequences containing only G and C nucleotides were found to generate a reasonable number of DNA fragments that were separable in agarose gels by field-inversion gel electrophoresis. The sizes of the DNA fragments were calibrated with a lambda DNA ladder and lambda DNA restriction fragments. The sum of fragment sizes obtained with restriction digests yielded a value for the chromosome of 1,980 kilobase pairs. Hybridization of a labeled fragment with two or more fragments from a digest with a different restriction enzyme provided the information needed to construct a circular map of the H. influenzae chromosome.
Kauc
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Department of Microbiology, University of Pennsylvania, Philadelphia 19104.
Mitchell
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M
Goodgal
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SH
D002876:Chromosomes, Bacterial / Q000648:ultrastructure*; D004269:DNA, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D006193:Haemophilus influenzae / Q000235:genetics*; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D015183:Restriction Mapping
D004269:DNA, Bacterial