CLONING AND CHARACTERIZATION OF NEISSERIA-MENINGITIDIS GENES ENCODINGTHE TRANSFERRIN-BINDING PROTEINS TBP1 AND TBP2

Genes tbp1 and tbp2, encoding the transferrin-binding proteins Tbp1 an d Tbp2, have been isolated from two strains of Neisseria meningitidis. The tbp2 and tbp1 open reading frames are tandemly arranged in the ge nome with an 87-bp intergenic region, and the DNA region upstream from the tbp2-coding sequence contains domains homologous to Escherichia c oli promoter consensus motives. Nucleotide sequence analysis suggests the existence of a Tbp1 precursor carrying an N-terminal signal peptid e with a peptidase I cleavage site and of a Tbp2 precursor with N-term inal homology to lipoproteins, including a peptidase II cleavage site. Comparison of the Tbp1 deduced amino acid (aa) sequences from both st rains showed about 76% aa homology, while those of Tbp2 revealed only about 47% aa homology. These comparisons should be extended to other N eisseria strains in order to evaluate further this genetic divergence further.