Signal-arrest-release (SAR) endolysin with lysozyme activity that degrades host peptidoglycans and participates with the pinholin and spanin proteins in the sequential events which lead to programmed host cell lysis releasing the mature viral particles. Once the pinholin has permeabilized the host cell membrane, the SAR-endolysin is released into the periplasm where it breaks down the peptidoglycan layer. Hydrolysis of (1->4)-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrins. Secreted as a signal-anchored, membrane-tethered, inactive endolysin which is subsequently refolded, activated and released by membrane depolarization driven by the pinholin. The signal-anchor, which may also be an uncleaved signal sequence tethers the SAR-endolysin to the membrane until the latter is depolarized by the holin, resulting in the escape of SAR-endolysin from the membrane. Belongs to the glycosyl hydrolase 24 family.