title: A novel peptidyl-prolyl cis/trans isomerase from Escherichia coli.
abstract: A novel peptidyl-prolyl cis/trans isomerase was isolated from Escherichia coli cell extract and characterized partially. Determination of the molecular mass by electrospray mass spectrometry indicated a protein of 10102 +/- 2 Da, smaller than cyclophilins or FK 506 binding proteins currently known. The specificity constant kcat/Km determined with Succinyl-Ala-Xaa-Pro-Phe-4-nitroanilide (Xaa = Leu) had a value comparable to those from cyclophilins from the same organism. However, the pattern of subsite specificity (Xaa = Gly, Ala, Val, Ile, Leu, Phe, Trp, His, Lys and Glu) was reminiscent of FK506 binding peptidyl-prolyl cis/trans isomerases. The enzyme activity was not inhibited by cyclosporin A or FK506 at inhibitor concentrations of < 5 microM, concentrations that affect most bacterial peptidyl-prolyl cis/trans isomerases. Computer-assisted analysis of 21 amino acid residues of the N-terminus determined by Edman degradation revealed no homology to known peptidyl-prolyl cis/trans isomerases.
authors.affiliation: Max-Planck-Gesellschaft, Arbeitsgruppe Enzymologie der Peptidbindung, Halle/Saale, Germany.
authors.forename: J U
authors.initials: JU
authors.lastname: Rahfeld
authors.forename: A
authors.initials: A
authors.lastname: Schierhorn
authors.forename: K
authors.initials: K
authors.lastname: Mann
authors.forename: G
authors.initials: G
authors.lastname: Fischer
mesh_terms: D000591:Amino Acid Isomerases / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D002352:Carrier Proteins; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase