Nucleotide sequence of a cluster of genes involved in the transformation of Haemophilus influenzae Rd》.pdfVIP

Gene, 104 (199 1) l-10 0 1991 Elsevier Science Publishers B.V. All rights reserved 0378-l 119/91/$03.50 1 GENE 05048 Nucleotide sequence of a cluster of genes involved in the transformation of Haemophilus inj7uenzae Rd (Uptake signal sequence; transcription terminator; penicillin-binding protein; DNA transport) Jean-Franqois Tomb, Hiyam El-Hajj and Hamilton 0. Smith Department of Molecular Biology and Genetics, The Johns Hopkins UniversitySchool of Medicine, Baltimore, MD 21205-2185 (U.S.A.) Received by F. Barany: 25 February 1991 Revised: 11 March 1991 Accepted: 17 April 1991 SUMMARY A genetic locus implicated in the development of competence in Haemophilus inzuenzae Rd has been previously mapped to a 12.8-kb PstI region of the chromosome [Tomb et al., J. Bacterial. 171 (1989) 3796-38021. To define the boundaries of this locus and to identify the gene(s) involved in transformation, additional mini-Tnl0kan mutagenesis was performed and the region containing all mutagenic insertions was sequenced. Three new transformation-deficient (Tfo-) mutants were found, bringing the number of distinct mutations mapped to this region up to eight. The transformation frequency of strains carrying the new insertions was 25 to 105-fold less than wild type. The ends of the mini-TnlfXan element were used as starting points