Distribution of a family of Haemophilus influenzae genes containing CCAA nucleotide repeating units

A family of genes containing lengths of CCAA nucleotide repeating units dir ectly following the sequence encoding the leader peptide has been identifie d in Haemophilus influenzae. The length of the CCAA repeats ranges from 6 t o 43 and all of the identified genes encode proteins or predicted proteins with a significant homology to bacterial iron- or heme-related outer membra ne proteins. We have previously shown that two of these gene products, HgpA and HgpB, bind hemoglobin and the hemoglobin-haptoglobin complex. Studies were performed to define the species distribution of the five identified ge nes and the CCAA repeats. We show that both the CCAA motif and the structur al genes for hemoglobin and hemoglobin-haptoglobin binding are widely distr ibuted among H. influenzae strains. (C) 1999 Published by Elsevier Science B.V. All rights reserved.