The major outer-membrane proteins of Chlamydia trachomatis serovars A and B: intra-serovar amino acid changes do not alter specificities of serovar- and C subspecies-reactive antibody-binding domains

J Gen Microbiol. 1990 Aug;136(8):1559-66. doi: 10.1099/00221287-136-8-1559.


The major outer-membrane protein (MOMP) of Chlamydia trachomatis is a promising candidate antigen for chlamydial vaccine development. We have sequenced the MOMP genes for a serovar A and a serovar B isolate and have compared these new sequences with those already reported. Intra-serovar changes in the inferred amino acid sequences of the surface-exposed variable segments known to be responsible for binding of neutralizing antibody were observed. Nevertheless, epitope mapping with solid-phase peptides showed that these intra-serovar changes did not affect the binding of serovar- and subspecies-specific, potentially protective antibodies. Variable segment 1 of C. trachomatis serovar A contained two adjacent antibody-binding sites, one of which was C-subspecies specific while the other was serovar A specific. Therefore the subspecies binding site for C-complex organisms is in variable segment 1, whilst that for B-complex organisms is in variable segment 4. This work shows that MOMP sequences are relatively stable within the serovar categorization for isolates taken decades apart from different continents. Within a given serovar, however, limited interchange of functionally related amino acids may occur without impairing the binding of serovar-specific antibody.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Monoclonal / immunology
  • Antibody Specificity
  • Antigens, Bacterial / genetics*
  • Bacterial Outer Membrane Proteins / immunology*
  • Bacterial Vaccines / genetics*
  • Base Sequence
  • Binding Sites
  • Chlamydia trachomatis / genetics
  • Chlamydia trachomatis / immunology*
  • Epitopes / genetics
  • Genes, Bacterial
  • Genomic Library
  • Molecular Sequence Data


  • Antibodies, Monoclonal
  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Vaccines
  • Epitopes

Associated data

  • GENBANK/M33535
  • GENBANK/M33536