Open AccessCharacterization of Mip proteins of Legionella pneumophila
Author(s) -
Ludwig Birgit,
Rahfeld Jens,
Schmidt Bettina,
Mann Karlheinz,
Wintermeyer Eva,
Fischer Gunter,
Hacker Jörg
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb06798.x
Subject(s) - legionella pneumophila , escherichia coli , biology , peptidylprolyl isomerase , biochemistry , microbiology and biotechnology , recombinant dna , isomerase , virulence , site directed mutagenesis , cis trans isomerases , mutagenesis , virulence factor , enzyme , bacteria , gene , mutation , mutant , genetics
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.