ID   PEMK_ECOLX              Reviewed;         133 AA.
AC   P13976;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1990, sequence version 1.
DT   25-MAY-2022, entry version 107.
DE   RecName: Full=Endoribonuclease PemK;
DE            EC=3.1.-.-;
DE   AltName: Full=Kid toxin protein;
DE   AltName: Full=mRNA interferase PemK;
GN   Name=pemK;
OS   Escherichia coli.
OG   Plasmid IncFII R100 (NR1), and Plasmid IncFII R1.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   PLASMID=IncFII R100 (NR1);
RX   PubMed=3019092; DOI=10.1016/0065-227x(86)90018-3;
RA   Ohtsubo H., Ryder T.B., Maeda Y., Armstrong K., Ohtsubo E.;
RT   "DNA replication of the resistance plasmid R100 and its control.";
RL   Adv. Biophys. 21:115-133(1986).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   PLASMID=IncFII R1;
RX   PubMed=3323833; DOI=10.1007/bf00337764;
RA   Bravo A., de Torrontegui G., Diaz R.;
RT   "Identification of components of a new stability system of plasmid R1,
RT   ParD, that is close to the origin of replication of this plasmid.";
RL   Mol. Gen. Genet. 210:101-110(1987).
RN   [3]
RP   FUNCTION.
RX   PubMed=2832364; DOI=10.1128/jb.170.4.1461-1466.1988;
RA   Tsuchimoto S., Ohtsubo H., Ohtsubo E.;
RT   "Two genes, pemK and pemI, responsible for stable maintenance of resistance
RT   plasmid R100.";
RL   J. Bacteriol. 170:1461-1466(1988).
RN   [4]
RP   FUNCTION, AND DNA-BINDING.
RX   PubMed=8455570; DOI=10.1007/bf00282787;
RA   Tsuchimoto S., Ohtsubo E.;
RT   "Autoregulation by cooperative binding of the PemI and PemK proteins to the
RT   promoter region of the pem operon.";
RL   Mol. Gen. Genet. 237:81-88(1993).
RN   [5]
RP   X-RAY CRYSTALLOGRAPHY (1.4 ANGSTROMS) OF 24-133, AND SUBUNIT.
RC   PLASMID=IncFII R1;
RX   PubMed=12377128; DOI=10.1016/s0969-2126(02)00856-0;
RA   Hargreaves D., Santos-Sierra S., Giraldo R., Sabariegos-Jareno R.,
RA   de la Cueva-Mendez G., Boelens R., Diaz-Orejas R., Rafferty J.B.;
RT   "Structural and functional analysis of the kid toxin protein from E. coli
RT   plasmid R1.";
RL   Structure 10:1425-1433(2002).
CC   -!- FUNCTION: Toxic component of a type II toxin-antitoxin (TA) system.
CC       Probably functions as an endoribonuclease. Responsible for the stable
CC       maintenance of the plasmid during cell division by postsegregational
CC       killing of plasmid-less daughter cells. Neutralized by coexpression
CC       with cognate antitoxin PemI. Both PemI and PemK proteins bind to the
CC       promoter region of the pem operon to autoregulate their synthesis.
CC       {ECO:0000269|PubMed:2832364, ECO:0000269|PubMed:8455570}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000269|PubMed:12377128}.
CC   -!- SIMILARITY: Belongs to the PemK/MazF family. {ECO:0000305}.
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DR   EMBL; M26840; AAA26070.1; -; Genomic_DNA.
DR   EMBL; X06240; CAA29585.1; -; Genomic_DNA.
DR   PIR; I64784; I64784.
DR   RefSeq; NP_862963.1; NC_004998.1.
DR   RefSeq; NP_957647.1; NC_005327.1.
DR   RefSeq; WP_001398199.1; NZ_WWEV01000284.1.
DR   RefSeq; YP_001816577.1; NC_010558.1.
DR   RefSeq; YP_003108265.1; NC_013121.1.
DR   RefSeq; YP_003937673.1; NC_014615.1.
DR   RefSeq; YP_006954227.1; NC_019095.1.
DR   PDB; 1M1F; X-ray; 1.40 A; A/B=24-133.
DR   PDB; 2C06; NMR; -; A/B=24-133.
DR   PDBsum; 1M1F; -.
DR   PDBsum; 2C06; -.
DR   AlphaFoldDB; P13976; -.
DR   BMRB; P13976; -.
DR   SMR; P13976; -.
DR   GeneID; 58462571; -.
DR   EvolutionaryTrace; P13976; -.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0004519; F:endonuclease activity; IEA:UniProtKB-KW.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   Gene3D; 2.30.30.110; -; 1.
DR   InterPro; IPR003477; PemK-like.
DR   InterPro; IPR011067; Plasmid_toxin/cell-grow_inhib.
DR   PANTHER; PTHR33988; PTHR33988; 1.
DR   Pfam; PF02452; PemK_toxin; 1.
DR   PIRSF; PIRSF033490; MazF; 1.
PE   1: Evidence at protein level;
KW   3D-structure; DNA-binding; Endonuclease; Hydrolase; Nuclease; Plasmid;
KW   RNA-binding; Toxin-antitoxin system.
FT   CHAIN           1..133
FT                   /note="Endoribonuclease PemK"
FT                   /id="PRO_0000201901"
FT   STRAND          28..33
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   STRAND          44..50
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   HELIX           54..60
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   STRAND          64..69
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   STRAND          72..76
FT                   /evidence="ECO:0007829|PDB:2C06"
FT   STRAND          81..83
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   STRAND          93..96
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   HELIX           105..108
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   STRAND          111..115
FT                   /evidence="ECO:0007829|PDB:1M1F"
FT   HELIX           118..129
FT                   /evidence="ECO:0007829|PDB:1M1F"
SQ   SEQUENCE   133 AA;  14822 MW;  25045682271E287A CRC64;
     MLKYQLKNEN GWMHRRLVRR KSDMERGEIW LVSLDPTAGH EQQGTRPVLI VTPAAFNRVT
     RLPVVVPVTS GGNFARTAGF AVSLDGVGIR TTGVVRCDQP RTIDMKARGG KRLERVPETI
     MNEVLGRLST ILT