title: Antibacterial activity of a cell wall hydrolase from Lactobacillus paracasei NRRL B-50314 produced by recombinant Bacillus megaterium.
abstract: The cell-free supernatant (CFS) from Lactobacillus paracasei NRRL B-50314 culture has been previously reported as containing antibacterial activity against a wide variety of Gram-positive bacteria. The CFS protein gel slice corresponding to antibacterial activities was subjected to trypsin digestion and ion trap MASS (Gel/LC-MS/MS) analysis. BlastP search of the resulted IQAVISIAEQQIGKP sequence led to a hypothetical cell-wall associated hydrolase (designated as CWH here) from Lactobacillus paracasei ATCC 25302. Further analyses of CWH revealed that the IQAVISIAEQQIGKP belongs to a highly conserved region of the NlpC/P60 superfamily. The L. paracasei NRRL B-50314 CWH gene, cloned in pStrepHIS1525CWH477, was introduced into Bacillus megaterium MS 941. The production of CWH477 protein was induced by xylose. The CWH477 protein was purified by using NiNTA column, and elution fraction E2 showed highest antibacterial activity. This study and bioinformatics analyses suggested that the antibacterial activity of CWH could originate from its cell wall degrading enzymatic function.
authors.affiliation: RPT Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 N. University St, Peoria, IL, 61604, USA, siqing.liu@ars.usda.gov.
authors.forename: Siqing
authors.initials: S
authors.lastname: Liu
authors.forename: Joseph O
authors.initials: JO
authors.lastname: Rich
authors.forename: Amber
authors.initials: A
authors.lastname: Anderson
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001410:Bacillus megaterium / Q000378:metabolism*; D002473:Cell Wall / Q000201:enzymology*; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D019295:Computational Biology; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006867:Hydrolases / Q000096:biosynthesis / Q000494:pharmacology*; D007778:Lactobacillus / Q000201:enzymology*; D008969:Molecular Sequence Data; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis; D053719:Tandem Mass Spectrometry; D014994:Xylose / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D011994:Recombinant Proteins; D014994:Xylose; D006867:Hydrolases