Lactococcus lactis Gene yjgB Encodes a γ- d -Glutaminyl- l -Lysyl- Endopeptidase Which Hydrolyzes Peptidoglycan
| Autor: | Carine Huard, Pascal Courtin, Christine Mézange, Marie-Pierre Chapot-Chartier, Yulia Redko |
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| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Ecology biology Lactococcus lactis Peptide Gene Expression Regulation Bacterial Peptidoglycan biology.organism_classification Applied Microbiology and Biotechnology Endopeptidase chemistry.chemical_compound Lysyl endopeptidase Bacterial Proteins chemistry Biochemistry Genes Bacterial Endopeptidases Enzymology and Protein Engineering Peptide sequence Histidine Food Science Biotechnology Binding domain |
| Zdroj: | Applied and Environmental Microbiology. 73:5825-5831 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.00705-07 |
| Popis: | YjgB is one of five peptidoglycan hydrolases previously identified in Lactococcus lactis . Analysis of its amino acid sequence revealed that YjgB contains an NlpC/P60 domain, whereas no specific cell wall binding domain or motif could be identified. The NlpC/P60 family is characterized by three conserved residues, a cysteine, a histidine, and a polar residue. In agreement with the presence of a Cys residue in the catalytic site of YjgB, its enzymatic activity was enhanced in the presence of dithiothreitol. Peptidoglycan-hydrolyzing activity of YjgB was detected in growing cells of an L. lactis strain overexpressing YjgB, as revealed by the presence of disaccharide (DS)-dipeptide in the muropeptide composition of the overexpressing strain. YjgB hydrolyzes the peptide chains of L. lactis muropeptides between γ- d -Gln and l -Lys residues. Its hydrolytic activity was detected on DSs with tetra- and pentapeptide chains, whereas hydrolytic activity was very low on DS-tripeptides. Thus, we demonstrated that YjgB is an endopeptidase which cleaves γ- d -Gln- l -Lys bonds in peptide chains of L. lactis peptidoglycan. |
| Databáze: | OpenAIRE |
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