Organization of the Haemophilus influenzae Rd genome

We present the first complete map of the Haemophilus influenzae genome, consisting of a detailed restriction map with a number of genetic loci. All of the ApaI, SmaI, and RsrII restriction sites (total of 45 sites) were mapped by Southern blot hybridization analysis of fragments separated by pulsed-field gel electrophoresis. Cloned genes were placed on the restriction map by Southern hybridization, and antibiotic resistance loci were also located by transformation with purified restriction fragments. The attachment site of the HP1 prophage was mapped. In addition, the number, locations, and orientations of the six rRNA operons in the H. influenzae chromosome were determined. The positions of conserved restriction sites in these rrn operons confirm that the direction of transcription is 16S to 23S, as in most other bacteria. The widely used strain BC200 appears to contain an unexpected 45-kilobase duplication.