title: Identification of the prolyl isomerase domain of Escherichia coli trigger factor.
abstract: E. coli trigger factor is a protein of 48 kDa which was recently identified as a ribosome-bound peptidyl-prolyl-cis/transisomerase (PPIase) capable of catalysing protein folding in vitro. We found trigger factor in association with nascent polypeptide chains, suggesting a function in the co-translational folding of proteins. Sequence comparisons revealed a homology of a segment of trigger factor with PPIases of the FK506 binding protein (FKBP) family. Here, we report on the purification of trigger factor and a domain assignment of its polypeptide chain by microsequencing and mass spectroscopy of proteolytic fragments. Two proteases generated fragments of 12-13 kDa molecular weight that encompass the predicted FKBP domain and possess PPIase activity in vitro. Sequence alignment of the known trigger factor proteins demonstrates a high degree of conservation within this central functional domain of the protein.
authors.affiliation: Zentrum für Molekulare Biologie, Universität Heidelberg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Hesterkamp
authors.forename: B
authors.initials: B
authors.lastname: Bukau
mesh_terms: D000591:Amino Acid Isomerases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D010450:Endopeptidases; D004926:Escherichia coli / Q000201:enzymology*; D006360:Heat-Shock Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D019696:Peptidylprolyl Isomerase; D011485:Protein Binding; D016415:Sequence Alignment; D017421:Sequence Analysis; D013329:Structure-Activity Relationship; D022021:Tacrolimus Binding Proteins
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D010446:Peptide Fragments; D010450:Endopeptidases; D000591:Amino Acid Isomerases; D022021:Tacrolimus Binding Proteins; D019696:Peptidylprolyl Isomerase