ID   VAPB1_HAEI8             Reviewed;          78 AA.
AC   Q4QNL8;
DT   03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2005, sequence version 1.
DT   25-MAY-2022, entry version 69.
DE   RecName: Full=Antitoxin VapB1;
DE   AltName: Full=NTHi VapB1 {ECO:0000303|PubMed:27672196};
GN   Name=vapB1; OrderedLocusNames=NTHI0439;
OS   Haemophilus influenzae (strain 86-028NP).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Pasteurellales;
OC   Pasteurellaceae; Haemophilus.
OX   NCBI_TaxID=281310;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=86-028NP;
RX   PubMed=15968074; DOI=10.1128/jb.187.13.4627-4636.2005;
RA   Harrison A., Dyer D.W., Gillaspy A., Ray W.C., Mungur R., Carson M.B.,
RA   Zhong H., Gipson J., Gipson M., Johnson L.S., Lewis L., Bakaletz L.O.,
RA   Munson R.S. Jr.;
RT   "Genomic sequence of an otitis media isolate of nontypeable Haemophilus
RT   influenzae: comparative study with H. influenzae serotype d, strain KW20.";
RL   J. Bacteriol. 187:4627-4636(2005).
RN   [2]
RP   INDUCTION, AND OPERON STRUCTURE.
RC   STRAIN=86-028NP;
RX   PubMed=17496075; DOI=10.1128/jb.00290-07;
RA   Daines D.A., Wu M.H., Yuan S.Y.;
RT   "VapC-1 of nontypeable Haemophilus influenzae is a ribonuclease.";
RL   J. Bacteriol. 189:5041-5048(2007).
RN   [3]
RP   FUNCTION.
RX   PubMed=25391136; DOI=10.1371/journal.pone.0112921;
RA   Hamilton B., Manzella A., Schmidt K., DiMarco V., Butler J.S.;
RT   "Analysis of non-typeable Haemophilous influenzae VapC1 mutations reveals
RT   structural features required for toxicity and flexibility in the active
RT   site.";
RL   PLoS ONE 9:E112921-E112921(2014).
RN   [4]
RP   FUNCTION, SUBUNIT, AND MUTAGENESIS OF THR-46; PHE-49; ASP-57; GLU-58;
RP   PHE-60 AND ARG-67.
RC   STRAIN=86-028NP;
RX   PubMed=27672196; DOI=10.1128/jb.00529-16;
RA   Walling L.R., Butler J.S.;
RT   "Structural determinants for antitoxin identity and insulation of cross
RT   talk between homologous toxin-antitoxin systems.";
RL   J. Bacteriol. 198:3287-3295(2016).
CC   -!- FUNCTION: Antitoxin component of a type II toxin-antitoxin (TA) system
CC       (PubMed:25391136, PubMed:27672196). Neutralizes the effect of cognate
CC       toxin VapC1 (PubMed:25391136, PubMed:27672196) but not non-cognate
CC       toxin VapC2 (PubMed:27672196). {ECO:0000269|PubMed:25391136,
CC       ECO:0000269|PubMed:27672196}.
CC   -!- SUBUNIT: Forms a complex with VapC1, and a weak complex with VapC2
CC       (PubMed:27672196). {ECO:0000269|PubMed:27672196}.
CC   -!- INDUCTION: More highly expressed in early growth phase, expression
CC       decreases as cell density decreases. Part of the vapB1-vapC1 operon.
CC       {ECO:0000269|PubMed:17496075}.
CC   -!- SIMILARITY: Belongs to the VapB family. {ECO:0000305}.
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DR   EMBL; CP000057; AAX87379.1; -; Genomic_DNA.
DR   RefSeq; WP_005649046.1; NC_007146.2.
DR   AlphaFoldDB; Q4QNL8; -.
DR   SMR; Q4QNL8; -.
DR   EnsemblBacteria; AAX87379; AAX87379; NTHI0439.
DR   GeneID; 66614919; -.
DR   KEGG; hit:NTHI0439; -.
DR   HOGENOM; CLU_162018_2_1_6; -.
DR   OMA; HITRVFQ; -.
DR   OrthoDB; 2047723at2; -.
DR   Proteomes; UP000002525; Chromosome.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   InterPro; IPR007159; SpoVT-AbrB_dom.
DR   InterPro; IPR037914; SpoVT-AbrB_sf.
DR   Pfam; PF04014; MazE_antitoxin; 1.
DR   SMART; SM00966; SpoVT_AbrB; 1.
DR   SUPFAM; SSF89447; SSF89447; 1.
DR   PROSITE; PS51740; SPOVT_ABRB; 1.
PE   1: Evidence at protein level;
KW   DNA-binding; Toxin-antitoxin system.
FT   CHAIN           1..78
FT                   /note="Antitoxin VapB1"
FT                   /id="PRO_0000408043"
FT   DOMAIN          3..44
FT                   /note="SpoVT-AbrB"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01076"
FT   MUTAGEN         46
FT                   /note="T->W: Now functions as an antitoxin against cognate
FT                   toxin VapC1 and non-cognate toxin VapC2, forms a complex
FT                   with both."
FT                   /evidence="ECO:0000269|PubMed:27672196"
FT   MUTAGEN         49
FT                   /note="F->V: No effect on antitoxin function against
FT                   VapC1."
FT                   /evidence="ECO:0000269|PubMed:27672196"
FT   MUTAGEN         57
FT                   /note="D->A: No effect on antitoxin function against
FT                   VapC1."
FT                   /evidence="ECO:0000269|PubMed:27672196"
FT   MUTAGEN         58
FT                   /note="E->A: No effect on antitoxin function against
FT                   VapC1."
FT                   /evidence="ECO:0000269|PubMed:27672196"
FT   MUTAGEN         60
FT                   /note="F->L: No effect on antitoxin function against
FT                   VapC1."
FT                   /evidence="ECO:0000269|PubMed:27672196"
FT   MUTAGEN         67
FT                   /note="R->G: No effect on antitoxin function against
FT                   VapC1."
FT                   /evidence="ECO:0000269|PubMed:27672196"
SQ   SEQUENCE   78 AA;  9037 MW;  468D048ED7C5C720 CRC64;
     MLTKVFQSGN SQAVRIPMDF RFDVDTVEIF RKENGDVVLR PVSKKTDDFL ALFEGFDETF
     IQALEARDDL PPQERENL