The Enterococcus hirae Mur‐2 enzyme displays N‐acetylglucosaminidase activity

Abstract

Enterococcus hirae produces two autolytic enzymes named Mur-1 and Mur-2, both previously described as N-acetylmuramidases. We used tandem mass spectrometry to show that Mur-2 in fact displays N-acetylglucosaminidase activity. This result reveals that Mur-2 and its counterparts studied to date, which are members of glycosyl hydrolase family 73 from the CAZy (Carbohydrate-Active enZyme) database, display the same catalytic activity.

Structural basis for autoinhibition and activation of Auto, a virulence‐associated peptidoglycan hydrolase of Listeria monocytogenes

“…Recently, some family members have also been identified as N ‐acetylglucosaminidases, consistent with our analyses. They include AtlA from Enterococcus faecalis (53% sequence identity), AcmA (51%) and AcmB (40%) from Lactococcus lactis , Mur‐2 from Enterococcus hirae (51%) and LytG from Bacillus subtilis (50%) (Horsburgh et al ., 2003; Huard et al ., 2003; Steen et al ., 2005; Eckert et al ., 2006; 2007).…”

Cellular chaining influences biofilm formation and structure in group A Streptococcus

“…In GAS, the gene mur1.2 encodes a peptidoglycan hydrolase belonging to the glucosyl hydrolase family 73 [ 38 ], members of which have been experimentally demonstrated to exhibit N-acetylglucosaminidase activity [ 39 ]. As the homologues LytB in both S. pneumoniae and S. gordonii [ 30 , 40 ] are involved in cell separation and chaining, it had been predicted that Mur1.2 performs a similar role in GAS [ 30 ].…”

Mechanistic Insights into the Activities of Major Families of Enzymes in Bacterial Peptidoglycan Assembly and Breakdown

“…[126][127][128] Gram-positive bacteria are known to use glucosaminidases and muramidases for cell separation, growth, and peptidoglycan recycling. [129][130][131][132][133][134][135][136] For instance, E. faecalis engages the glucosaminidase AtlA and muramidase AtlB in cell separation. [137,138] S. aureus requires four glucosaminidases (namely AtlA/GlcA, SagA, ScaH, SagB) to maintain normal cell morphology and growth.…”

“…Gram‐positive bacteria are known to use glucosaminidases and muramidases for cell separation, growth, and peptidoglycan recycling [129–136] . For instance, E. faecalis engages the glucosaminidase AtlA and muramidase AtlB in cell separation [137,138] .…”