title: Characterization and expression of adjacent proline iminopeptidase and aspartase genes from Eikenella corrodens.
abstract: Two adjacent genes involved in nitrogen metabolism from Eikenella corrodens, with a potential role in pathogenesis, were studied. Proline iminopeptidase (Pip) activity, which may be essential for energy production and protection against host immune mechanisms, is exhibited by E. corrodens. Analysis of Pip-expressing clones revealed an ORF of 939 bases with a predicted amino acid sequence identity of 67% to the Pip of Neisseria gonorrhoea. 200 bp downstream from pip, an ORF of 1395 bases, encoding a protein with 87% identity to a putative aspartase from the Neisseria meningitidis genome sequence, was identified. Enzymatic function was confirmed with a complemented Escherichia coli aspartase deficient mutant. The E. corrodens aspartase was found to be 77% identical to the Haemophilus influenzae aspartase sequence, which was originally identified on the basis of its ability to bind plasminogen. However, the E. corrodens aspartase had no such activity. Southern hybridization indicated both genes to be single copy and conserved within the genomes of a diverse panel of E. corrodens isolates from health and disease.
authors.affiliation: University of Bristol Dental School, Lower Maudlin Street, Bristol BS1 2LY, UK.
authors.forename: T
authors.initials: T
authors.lastname: Selby
authors.forename: R P
authors.initials: RP
authors.lastname: Allaker
authors.forename: D
authors.initials: D
authors.lastname: Dymock
mesh_terms: D000626:Aminopeptidases / Q000235:genetics*; D001220:Aspartate Ammonia-Lyase / Q000235:genetics*; D017124:Conserved Sequence; D016124:Eikenella corrodens / Q000201:enzymology* / Q000235:genetics*; D015870:Gene Expression; D005798:Genes, Bacterial; D006193:Haemophilus influenzae / Q000201:enzymology / Q000235:genetics; D009344:Neisseria gonorrhoeae / Q000201:enzymology / Q000235:genetics; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D000626:Aminopeptidases; C022450:prolyl aminopeptidase; D001220:Aspartate Ammonia-Lyase