Characterization of Mip proteins of Legionella pneumophila.
The Mip ('macrophage infectivity potentiator') protein of Legionella pneumophila has been shown to be an essential virulence factor, exhibiting peptidyl-prolyl cis/trans isomerase (PPIase) activity that can be inhibited by the immunosuppressant FK506. The cloning and sequencing of mip genes from three different L. pneumophila strains revealed a single amino acid substitution which did not affect the isomerase property of the enzyme. Mip proteins isolated from two wild-type L. pneumophila strains and from two corresponding Escherichia coli K-12 recombinant clones derived from these strains exhibited identical enzymatic properties and the precursor proteins are processed at identical cleavage sites. The mature Mip proteins exist in an oligomeric form. Site-directed mutagenesis demonstrated that a substitution of an Asp residue at position 142 by a Leu residue affects PPIase activity of Mip.
Ludwig
B
B
Institut für Molekulare Infektionsbiologie, Univ. Würzburg, FRG.
Rahfeld
J
J
Schmidt
B
B
Mann
K
K
Wintermeyer
E
E
Fischer
G
G
Hacker
J
J
D000591:Amino Acid Isomerases / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D005798:Genes, Bacterial / Q000235:genetics*; D020104:Immunophilins; D007700:Kinetics; D016952:Legionella pneumophila / Q000737:chemistry* / Q000235:genetics* / Q000472:pathogenicity; D008565:Membrane Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D019696:Peptidylprolyl Isomerase; D011487:Protein Conformation; D017421:Sequence Analysis; D017422:Sequence Analysis, DNA; D016559:Tacrolimus / Q000378:metabolism; D014774:Virulence
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D000591:Amino Acid Isomerases; D020104:Immunophilins; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase; D016559:Tacrolimus