title: A 28 kDa major immunogen of Chlamydia psittaci shares identity with Mip proteins of Legionella spp. and Chlamydia trachomatis-cloning and characterization of the C. psittaci mip-like gene.
abstract: Chlamydia psittaci strain guinea-pig inclusion conjunctivitis (GPIC) produces a self-limiting ocular infection of guinea-pigs, and this condition is a representative animal model of ocular chlamydial disease. Convalescent guinea-pigs, which are resistant to reinfection, produce antibodies to several elementary-body proteins, including an uncharacterized antigen of 28 kDa. Convalescent guinea-pig sera were used to identify, from a lambda expression library, two overlapping GPIC genomic clones that produced the 28 kDa antigenic protein. Nucleotide sequence analysis revealed that the gene coding for the 28 kDa protein was similar to the mip (macrophage infectivity potentiator) genes from Legionella pneumophila and Chlamydia trachomatis. The GPIC gene and its product were accordingly designated mip and Mip, respectively. Analysis of the regions flanking mip identified three tightly linked open reading frames coding for predicted products with sequence similarity to asparagine tRNA ligase (AspS), rRNA methylase (SpoU), and thioredoxin (TrxA). The arrangement of these genes in GPIC was aspS-mip-spoU-trxA. Sequence analysis of PCR products produced using genomic DNA from an ovine abortion strain of C. psittaci and from C. trachomatis strain LGV-434 demonstrated that the arrangement of mip, spoU and trxA is common among these chlamydiae.
authors.affiliation: Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, MT 59840, USA.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Rockey
authors.affiliation: Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, MT 59840, USA.
authors.forename: Brian B
authors.initials: BB
authors.lastname: Chesebro
authors.affiliation: Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, MT 59840, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Heinzen
authors.affiliation: Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, MT 59840, USA.
authors.forename: Ted
authors.initials: T
authors.lastname: Hackstadt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology*; D001483:Base Sequence; D002692:Chlamydia trachomatis / Q000235:genetics; D002691:Chlamydophila psittaci / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003235:Conjunctivitis, Inclusion / Q000276:immunology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006168:Guinea Pigs; D020104:Immunophilins; D016952:Legionella pneumophila / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D019696:Peptidylprolyl Isomerase; D016133:Polymerase Chain Reaction; D009956:Psittacosis / Q000276:immunology; D017386:Sequence Homology, Amino Acid
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D008565:Membrane Proteins; D020104:Immunophilins; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase