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Query: UNIPROT:P33763 (N-acetylmuramoyl-l-alanine amidase)
 28 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peptidoglycan recognition proteins (PGRPs) are pattern recognition molecules coded by up to 13 genes in insects and 4 genes in mammals. In insects PGRPs activate antimicrobial pathways in the hemolymph and cells, or are peptidoglycan (PGN)-lytic amidases. In mammals one PGRP is an antibacterial neutrophil protein. We report that human PGRP-L is a Zn2+-dependent N-acetylmuramoyl-l-alanine amidase (EC 3.5.1.28), an enzyme that hydrolyzes the amide bond between MurNAc and l-Ala of bacterial PGN. The minimum PGN fragment hydrolyzed by PGRP-L is MurNAc-tripeptide. PGRP-L has no direct bacteriolytic activity. The other members of the human PGRP family, PGRP-Ialpha, PGRP-Ibeta, and PGRP-S, do not have the amidase activity. The C-terminal region of PGRP-L, homologous to bacteriophage and bacterial amidases, is required and sufficient for the amidase activity of PGRP-L, although its activity (in the N-terminal delta1-343 deletion mutant) is reduced. The Zn2+ binding amino acids (conserved in PGRP-L and T7 amidase) and Cys-419 (not conserved in T7 amidase) are required for the amidase activity of PGRP-L, whereas three other amino acids, needed for the activity of T7 amidase, are not required for the activity of PGRP-L. These amino acids, although required, are not sufficient for the amidase activity, because changing them to the "active" configuration does not convert PGRP-S into an active amidase. In conclusion, human PGRP-L is an N-acetylmuramoyl-l-alanine amidase and this function is conserved in prokaryotes, insects, and mammals.
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PMID:Human peptidoglycan recognition protein-L is an N-acetylmuramoyl-L-alanine amidase. 1450 76

Clostridium perfringens is a gram-positive, spore-forming anaerobic bacterium that plays a substantial role in non-foodborne human, animal, and avian diseases as well as human foodborne disease. Previously discovered C. perfringens bacteriophage lytic enzyme amino acid sequences were utilized to identify putative prophage lysins or autolysins by BLAST analyses encoded by the genomes of C. perfringens isolates. A predicted N-acetylmuramoyl-L-alanine amidase or MurNAc-LAA (also known as peptidoglycan aminohydrolase, NAMLA amidase, NAMLAA, amidase 3, and peptidoglycan amidase; EC 3.5.1.28) was identified that would hydrolyze the amide bond between N-acetylmuramoyl and L-amino acids in certain cell wall glycopeptides. The gene encoding this protein was subsequently cloned from genomic DNA of a C. perfringens isolate by polymerase chain reaction, and the gene product (PlyCpAmi) was expressed to determine if it could be utilized as an antimicrobial to control the bacterium. By spot assay, lytic zones were observed for the purified amidase and the E. coli expression host cellular lysate containing the amidase gene. Turbidity reduction and plate counts of C. perfringens cultures were significantly reduced by the expressed protein and observed morphologies for cells treated with the amidase appeared vacuolated, non-intact, and injured compared to the untreated cells. Among a variety of C. perfringens strains, there was little gene sequence heterogeneity that varied from 1 to 21 nucleotide differences. The results further demonstrate that it is possible to discover lytic proteins encoded in the genomes of bacteria that could be utilized to control bacterial pathogens.
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PMID:Expression of a Clostridium perfringens genome-encoded putative N-acetylmuramoyl-L-alanine amidase as a potential antimicrobial to control the bacterium. 2393 74