Chlamydia antigens and corresponding DNA fragments and uses thereof

DETAILED DESCRIPTION The present invention provides purified and isolated polynucleotide molecules that encode the Chlamydia polypeptide designated 76 kDa protein (SEQ ID No: 1) which can be used in methods to prevent, treat, and diagnose Chlamydia infection.
In one form of the invention, the polynucleotide molecules are DNA that encode the polypeptide of SEQ ID No: 2.
Another form of the invention provides polypeptides corresponding to the isolated DNA molecules.
The amino acid sequence of the corresponding encoded polypeptide is shown as SEQ ID No: 2.
Another form of the invention provides truncated polypeptides corresponding to truncated DNA molecules.
In one embodiment, the truncated nucleotide and amino acid sequences are shown as SEQ ID Nos: 3 and 4 respectively.
In another embodiment, the truncated nucleotide and amino acid sequences are shown as SEQ ID Nos: 5 and 6 respectively.
Although Melgosa et al.
has reported cloning a 76 kDa protein from C.
pneumoniae, comparison of the gene sequence as reported by Melgosa et al.
to the published geneome sequence of C.
pneumoniae (http://chlamydia-www.
berkeley.
edu:4231/) reveals that, in fact, the genomic sequence in this region contains at least two open reading frames (ORFs), one in the 5' portion and one in the 3' portion.
The sequence reported in Melgosa et al.
is an in-frame fusion of the 5' end of the 5' ORF.
Thus, Melgosa's deduced protein is merely a 76 kDa fusion protein and not the 76 kDa protein observed by immunoblotting from various C.
pneumoniae isolates.
By contrast, the 76 kDa protein of the present invention is the full-length protein encoded by the 3'ORF in this region of the genome.
Notably, further analysis of the genome sequence (http://chlamydia-www.
berkeley.
edu:4231/) reveals at least one in-frame ATG upstream of the start codon of the 5' ORF, suggesting that the 5' ORF may form part of one or more larger ORFs.
Those skilled in the art will readily understand that the invention, having provided the polynucleotide sequences encoding the Chlamydia 76 kDa protein, also provides polynucleotides encoding fragments derived from such a polypeptide