title: Proline iminopeptidase gene from Xanthomonas campestris pv. citri.
abstract: The pip gene coding for the proline iminopeptidase (Pip) of Xanthomonas campestris pv. citri was cloned in an Escherichia coli leuB strain using a selective medium containing the dipeptide D-Ala-L-Leu as the sole source of L-leucine. Nucleotide sequencing of this gene revealed a 939 bp open reading frame encoding a 312 amino acid protein (35 126 Da). The deduced amino acid sequence showed 47% identity with the Pip from Neisseria gonorrhoeae. A lacZ-pip fusion gene was overexpressed in E. coli under the control of the Plac promoter. The Pip of X. campestris hydrolysed L-prolyl-p-nitroanilide with the highest efficiency, but was also able to hydrolyse L-alanyl-p-nitroanilide and D-alanyl-p-nitroanilide. The molecular mass of Pip was found to be 35 kDa by SDS-PAGE and 120 kDa by gel filtration, suggesting that the active enzyme is a multimer.
authors.affiliation: Departamento de Microbiología Molecular, Consejo Superior de Investigaciones Científicas, Velázquez, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Alonso
authors.forename: J L
authors.initials: JL
authors.lastname: García
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000813:Anilides / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial / Q000235:genetics*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D016959:Xanthomonas campestris / Q000201:enzymology / Q000235:genetics*
chemical_list: D000813:Anilides; D011993:Recombinant Fusion Proteins; D000626:Aminopeptidases; C022450:prolyl aminopeptidase