Nucleotide sequence of the major outer membrane protein gene fromChlamydia trachomatisserovar H

The gene encoding the major outer membrane protein (MOMP) from Chlamydia trachomatis, serovar H was isolated from a genomic library using the MOMP gene from serovar L2 as the probe (1) . The recombinant insert was subcloned into a plasmid vector (Bluescript), the gene localized by Southern blotting and the nucleotide sequence was determined by the dideoxy chain termination method. The H MOMP gene is 1193 bp long and encodes a polypeptide of 397 amino acids including a 22 amino acid leader sequence. This corresponds to a mature H MOMP of 40,672 daltons, in agreement with the molecular mass predicted by SDS-PAGE (2) . The H and L2 MOMP genes are 74% homologous at the nucleotide level and are 84% homologous in their protein sequences. The differences in the two sequences are clustered in four regions (435-483, 655-687, 906-952 and 1083-1194).