Two homologous oligopeptide binding protein genes (oppA) in Lactococcus lactis opp2 [corrected].
In previous studies, it has been shown that inactivation of opp or even oppA abolishes the capacity of Lactococcus lactis to utilize oligopeptides. We now show that the opp operon has been duplicated in L. lactis MG1363. The nucleotide sequence of the oppA and oppC homologues (appA and appC) and most of the oppB homologue (appB) indicate that the corresponding protein sequences are 83%, 92% and 91% identical, respectively. Inactivation of appA, via homologous recombination, as well as complementation studies were carried out to determine the possible function of appA in peptide utilization. As anticipated from studies with an oppA knock-out, peptide utilization was not impaired in an appA disruption mutant. Importantly, AppA expressed from a plasmid could restore the ability of oppA deletion mutants to utilize Leu-enkephalin, albeit with a lower efficiency than OppA. The differences in the ability to utilize this pentapeptide were not due to differences in expression levels but most likely reflect a different catalytic efficiency in oligopeptide utilization when AppA is used as ligand receptor.
Sanz
Yolanda
Y
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, NL 9751 NN, Haren, The Netherlands. yolsanz@iata.csic.es
Lanfermeijer
Frank C
FC
Hellendoorn
Michiel
M
Kok
Jan
J
Konings
Wil N
WN
Poolman
Bert
B
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D013294:Lactococcus lactis / Q000235:genetics*; D008074:Lipoproteins / Q000235:genetics* / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D009876:Operon; D010957:Plasmids / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D002352:Carrier Proteins; D008074:Lipoproteins; D009842:Oligopeptides; C046506:oligopeptide-binding protein, bacteria