title: In silico inference of inclusion membrane protein family in obligate intracellular parasites chlamydiae.
abstract: Chlamydiae are obligate intracellular pathogens that proliferate only inside a vacuole, called an inclusion. Chlamydial Inc proteins are known to be a major component of the inclusion membrane, but little is known about the gene number and function. The Inc proteins share very low sequence similarity but a similar hydropathy profile among them. Using the hydropathy profile, we computationally searched the open reading frames (ORFs) having a similar profile and predicted 90 and 36 ORFs (Inc-like ORFs) as candidates for Inc proteins in Chlamydia pneumoniae J138 and Chlamydia trachomatis serovar D, respectively. On the other hand, only a few Inc-like ORFs were found in organisms other than chlamydiae, suggesting that the Inc-like ORFs are specific to chlamydiae. Comparative genome analysis also revealed that the Inc-like ORFs have multiplied and diverged as paralogues and orthologues in the chlamydial genomes, and that some Inc-like ORFs lacked the N-terminal portion or encoded the split form. The data suggest that these gene products constitute a large protein family and may play an important role in chlamydial infection, growth and survival in the host cell.
authors.affiliation: Kitasato Institute for Life Sciences, Kitasato University, Kitasato 1-15-1, Sagamihara, Kanagawa 228-8555, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Toh
authors.forename: Koshiro
authors.initials: K
authors.lastname: Miura
authors.forename: Mutsunori
authors.initials: M
authors.lastname: Shirai
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
mesh_terms: D002693:Chlamydiaceae / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames
chemical_list: D008565:Membrane Proteins