Cloning and characterization of Neisseria meningitidis genes encoding the transferrin-binding proteins Tbp1 and Tbp2.

Abstract Genes tbpl and tbp2 , encoding the transferrin-binding proteins Tbpl and Tbp2, have been isolated from two strains of Neisseria meningitidis . The tbp2 and tbpl open reading frames are tandemly arranged in the genome with an 87-bp intergenic region, and the DNA region upstream from the tbp2-coding sequence contains domains homologous to Escherichia coli promoter consensus motives. Nucleotide sequence analysis suggests the existence of a Tbpl precursor carrying an N-terminal signal peptide with a peptidase I cleavage site and of a Tbp2 precursor with N-terminal homology to lipoproteins, including a peptidase II cleavage site. Comparison of the Tbpl deduced amino acid (aa) sequences from both strains showed about 76% aa homology, while those of Tbp2 revealed only about 47% aa homology. These comparisons should be extended to other Neisseria strains in order to evaluate further this genetic divergence further.