This family contains several Chlamydia polymorphic membrane proteins. Chlamydia pneumoniae is an obligate intracellular bacterium and a common human pathogen causing infection of the upper and lower respiratory tract. Common for the Pmps are the tetrapeptide GGA(I/V/L) motif repeated several times in the N-terminal part. The C-terminal half is characterised by conserved tryptophans and a carboxy-terminal phenylalanine. A signal peptide leader sequence is predicted in 20 C. pneumoniae Pmps, which indicates an outer membrane localisation. Pmp10 and Pmp11 contain a signal peptidase II cleavage site suggesting lipid modification. The C. pneumoniae pmp genes represent 17.5% of the chlamydia-specific coding capacity and they are all transcribed during chlamydial growth but the function of Pmps remains unknown [1]. This family shows some similarity to Pfam:PF05594 and hence is likely to also form a beta-helical structure (personal obs:C Yeats).

1: Differential expression of Pmp10 in cell culture infected with Chlamydia pneumoniae CWL029. Pedersen AS, Christiansen G, Birkelund S; FEMS Microbiol Lett 2001;203:153-159. PMID:11583841