ID ENLYS_BPP21 Reviewed; 165 AA. AC P27359; DT 01-AUG-1992, integrated into UniProtKB/Swiss-Prot. DT 01-AUG-1992, sequence version 1. DT 08-NOV-2023, entry version 90. DE RecName: Full=SAR-endolysin {ECO:0000255|HAMAP-Rule:MF_04136}; DE EC=3.2.1.17 {ECO:0000255|HAMAP-Rule:MF_04136}; DE AltName: Full=Endolysin {ECO:0000255|HAMAP-Rule:MF_04136}; DE AltName: Full=Lysis protein {ECO:0000255|HAMAP-Rule:MF_04136}; DE AltName: Full=Lysozyme {ECO:0000255|HAMAP-Rule:MF_04136}; DE AltName: Full=Muramidase {ECO:0000255|HAMAP-Rule:MF_04136}; GN Name=R; OS Enterobacteria phage P21 (Bacteriophage 21) (Bacteriophage P21). OC Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes; OC Lambdavirus; Lambdavirus lambda. OX NCBI_TaxID=10711; OH NCBI_TaxID=562; Escherichia coli. RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=2019562; DOI=10.1128/jb.173.9.2897-2905.1991; RA Bonovich M.T., Young R.; RT "Dual start motif in two lambdoid S genes unrelated to lambda S."; RL J. Bacteriol. 173:2897-2905(1991). RN [2] {ECO:0007744|PDB:3HDE, ECO:0007744|PDB:3HDF} RP X-RAY CRYSTALLOGRAPHY (1.70 ANGSTROMS) OF 27-165, AND MUTAGENESIS OF RP 14-GLY-GLY-15. RX PubMed=19881499; DOI=10.1038/nsmb.1681; RA Sun Q., Kuty G.F., Arockiasamy A., Xu M., Young R., Sacchettini J.C.; RT "Regulation of a muralytic enzyme by dynamic membrane topology."; RL Nat. Struct. Mol. Biol. 16:1192-1194(2009). CC -!- FUNCTION: Signal-arrest-release (SAR) endolysin with lysozyme activity CC that degrades host peptidoglycans and participates with the pinholin CC and spanin proteins in the sequential events which lead to programmed CC host cell lysis releasing the mature viral particles. Once the pinholin CC has permeabilized the host cell membrane, the SAR-endolysin is released CC into the periplasm where it breaks down the peptidoglycan layer. CC {ECO:0000255|HAMAP-Rule:MF_04136}. CC -!- CATALYTIC ACTIVITY: CC Reaction=Hydrolysis of (1->4)-beta-linkages between N-acetylmuramic CC acid and N-acetyl-D-glucosamine residues in a peptidoglycan and CC between N-acetyl-D-glucosamine residues in chitodextrins.; CC EC=3.2.1.17; Evidence={ECO:0000255|HAMAP-Rule:MF_04136}; CC -!- SUBCELLULAR LOCATION: Host cell inner membrane {ECO:0000255|HAMAP- CC Rule:MF_04136}; Single-pass type II membrane protein CC {ECO:0000255|HAMAP-Rule:MF_04136}; Periplasmic side {ECO:0000255|HAMAP- CC Rule:MF_04136}. Note=Secreted as a signal-anchored, membrane-tethered, CC inactive endolysin which is subsequently refolded, activated and CC released by membrane depolarization driven by the pinholin. CC {ECO:0000255|HAMAP-Rule:MF_04136}. CC -!- DOMAIN: The signal-anchor, which may also be an uncleaved signal CC sequence tethers the SAR-endolysin to the membrane until the latter is CC depolarized by the holin, resulting in the escape of SAR-endolysin from CC the membrane. {ECO:0000255|HAMAP-Rule:MF_04136}. CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 24 family. CC {ECO:0000255|HAMAP-Rule:MF_04136}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; M65239; AAA32350.1; -; Genomic_DNA. DR PDB; 3HDE; X-ray; 1.95 A; A/B/C/D=1-165. DR PDB; 3HDF; X-ray; 1.70 A; A/B=27-165. DR PDBsum; 3HDE; -. DR PDBsum; 3HDF; -. DR SMR; P27359; -. DR CAZy; GH24; Glycoside Hydrolase Family 24. DR EvolutionaryTrace; P27359; -. DR GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell. DR GO; GO:0016020; C:membrane; IEA:UniProtKB-KW. DR GO; GO:0003796; F:lysozyme activity; IEA:UniProtKB-EC. DR GO; GO:0016998; P:cell wall macromolecule catabolic process; IEA:InterPro. DR GO; GO:0042742; P:defense response to bacterium; IEA:UniProtKB-KW. DR GO; GO:0031640; P:killing of cells of another organism; IEA:UniProtKB-KW. DR GO; GO:0009253; P:peptidoglycan catabolic process; IEA:InterPro. DR CDD; cd16900; endolysin_R21-like; 1. DR Gene3D; 1.10.530.40; -; 1. DR HAMAP; MF_04110; ENDOLYSIN_T4; 1. DR HAMAP; MF_04136; SAR_ENDOLYSIN; 1. DR InterPro; IPR034690; Endolysin_T4_type. DR InterPro; IPR002196; Glyco_hydro_24. DR InterPro; IPR023346; Lysozyme-like_dom_sf. DR InterPro; IPR023347; Lysozyme_dom_sf. DR InterPro; IPR043688; SAR_endolysin-like. DR PANTHER; PTHR38107; -; 1. DR PANTHER; PTHR38107:SF3; LYSOZYME RRRD-RELATED; 1. DR Pfam; PF00959; Phage_lysozyme; 1. DR SUPFAM; SSF53955; Lysozyme-like; 1. PE 1: Evidence at protein level; KW 3D-structure; Antimicrobial; Bacteriolytic enzyme; Cytolysis; Glycosidase; KW Host cell inner membrane; Host cell lysis by virus; Host cell membrane; KW Host membrane; Hydrolase; Membrane; Signal-anchor; Transmembrane; KW Transmembrane helix; Viral release from host cell. FT CHAIN 1..165 FT /note="SAR-endolysin" FT /id="PRO_0000218101" FT TRANSMEM 8..28 FT /note="Helical; Signal-anchor for type II membrane protein" FT /evidence="ECO:0000255" FT ACT_SITE 35 FT /note="Proton donor/acceptor" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04136, FT ECO:0000305|PubMed:19881499" FT ACT_SITE 44 FT /note="Proton donor/acceptor" FT /evidence="ECO:0000255|HAMAP-Rule:MF_04136, FT ECO:0000305|PubMed:19881499" FT MUTAGEN 14..15 FT /note="GG->LL: The SAR-endolysin remains tethered in the FT membrane and cannot be released; complete loss of lysis." FT /evidence="ECO:0000269|PubMed:19881499" FT HELIX 3..12 FT /evidence="ECO:0007829|PDB:3HDE" FT HELIX 13..15 FT /evidence="ECO:0007829|PDB:3HDE" FT HELIX 16..26 FT /evidence="ECO:0007829|PDB:3HDE" FT STRAND 30..35 FT /evidence="ECO:0007829|PDB:3HDE" FT STRAND 38..43 FT /evidence="ECO:0007829|PDB:3HDF" FT STRAND 49..52 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 68..86 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 87..89 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 96..109 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 114..125 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 128..136 FT /evidence="ECO:0007829|PDB:3HDF" FT TURN 139..141 FT /evidence="ECO:0007829|PDB:3HDF" FT STRAND 148..150 FT /evidence="ECO:0007829|PDB:3HDF" FT HELIX 152..163 FT /evidence="ECO:0007829|PDB:3HDF" SQ SEQUENCE 165 AA; 17996 MW; 14ECECD883232D3C CRC64; MPPSLRKAVA AAIGGGAIAI ASVLITGPSG NDGLEGVSYI PYKDIVGVWT VCHGHTGKDI MLGKTYTKAE CKALLNKDLA TVARQINPYI KVDIPETMRG ALYSLLYNVG AGNFRTSTLL RKINQGDIKG ACDQLRRWTY AGGKQWKGLM TRREIEREIC LWGQQ //