Molecular cloning of a Coxiella burnetii gene encoding a macrophage infectivity potentiator (Mip) analogue.
The gene encoding a protein that reacted with antibodies specific for Legionella pneumophila macrophage infectivity potentiator (LpMip) was cloned from Coxiella burnetii, the obligate intracellular rickettsia that causes Q fever in humans. Nucleotide sequencing analysis revealed an ORF encoding a gene product of 230 amino acids with a molecular mass of 25.5 kDa and a predicted pI of 10.7. The predicted amino acid sequence from the ORF shows similarity with Mip/Mip-like proteins of Legionella (46%) and Chlamydia (30%). Moreover, like LpMip, the amino acid sequence of the C terminus of this protein has over 35% identity to prokaryotic and eukaryotic FK506-binding proteins (FKBPs) that belong to a superfamily of immunophilins and are peptidyl-prolyl cis-trans isomerases (PPIases). When overproduced in Escherichia coli, the C. burnetii protein also exhibited PPIase activity. Taken together, these results demonstrate that C. burnetii encodes a Mip analogue (CbMip). A putative leader peptide at the N terminus of CbMip was detected by computer analysis. Furthermore, TnphoA mutagenesis demonstrated that in E. coli CbMip was secreted. In view of the role of Mip/Mip-like proteins in the pathogenesis of Legionella and Chlamydia, CbMip may be a C. burnetii virulence factor.
Mo
Y Y
YY
Department of Microbiology, Washington State University, Pullman 99164-4233, USA.
Cianciotto
N P
NP
Mallavia
L P
LP
D000591:Amino Acid Isomerases / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D002692:Chlamydia trachomatis / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D016997:Coxiella burnetii / Q000235:genetics* / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015870:Gene Expression; D005798:Genes, Bacterial; D020104:Immunophilins; D016952:Legionella pneumophila / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D002352:Carrier Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D000591:Amino Acid Isomerases; D020104:Immunophilins; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase; C068254:FkpA protein, E coli