ID   AAPA3_HELPY             Reviewed;          30 AA.
AC   P0DUM5;
DT   29-SEP-2021, integrated into UniProtKB/Swiss-Prot.
DT   29-SEP-2021, sequence version 1.
DT   23-FEB-2022, entry version 2.
DE   RecName: Full=Toxic protein AapA3 {ECO:0000303|PubMed:31411564};
GN   Name=aapA3 {ECO:0000303|PubMed:31411564}; OrderedLocusNames=HP_1432.1;
OS   Helicobacter pylori (strain ATCC 700392 / 26695) (Campylobacter pylori).
OC   Bacteria; Proteobacteria; Epsilonproteobacteria; Campylobacterales;
OC   Helicobacteraceae; Helicobacter.
OX   NCBI_TaxID=85962;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700392 / 26695;
RX   PubMed=9252185; DOI=10.1038/41483;
RA   Tomb J.-F., White O., Kerlavage A.R., Clayton R.A., Sutton G.G.,
RA   Fleischmann R.D., Ketchum K.A., Klenk H.-P., Gill S.R., Dougherty B.A.,
RA   Nelson K.E., Quackenbush J., Zhou L., Kirkness E.F., Peterson S.N.,
RA   Loftus B.J., Richardson D.L., Dodson R.J., Khalak H.G., Glodek A.,
RA   McKenney K., FitzGerald L.M., Lee N., Adams M.D., Hickey E.K., Berg D.E.,
RA   Gocayne J.D., Utterback T.R., Peterson J.D., Kelley J.M., Cotton M.D.,
RA   Weidman J.F., Fujii C., Bowman C., Watthey L., Wallin E., Hayes W.S.,
RA   Borodovsky M., Karp P.D., Smith H.O., Fraser C.M., Venter J.C.;
RT   "The complete genome sequence of the gastric pathogen Helicobacter
RT   pylori.";
RL   Nature 388:539-547(1997).
RN   [2]
RP   FUNCTION AS A TOXIN, ACTIVITY REGULATION, INDUCTION, AND MUTAGENESIS OF
RP   SER-9 AND 20-LEU--ARG-30.
RC   STRAIN=ATCC 700392 / 26695;
RX   PubMed=31411564; DOI=10.7554/elife.47549;
RA   Masachis S., Tourasse N.J., Lays C., Faucher M., Chabas S., Iost I.,
RA   Darfeuille F.;
RT   "A genetic selection reveals functional metastable structures embedded in a
RT   toxin-encoding mRNA.";
RL   Elife 8:0-0(2019).
CC   -!- FUNCTION: May be involved in response to oxidative stress (By
CC       similarity). Toxic component of a type I toxin-antitoxin (TA) system.
CC       Neutralized by cognate antisense RNA antitoxin IsoA3 RNA which forms an
CC       extensive duplex with the mRNA. The antitoxin gene cannot be deleted,
CC       indicating expression of AapA3 is toxic. Non-cognate antitoxin RNAs
CC       IsoA1, IsoA2, IsoA4, IsoA5 or IsoA6 are unable to neutralize aapA3
CC       (PubMed:31411564). Oxidative stress may trigger transformation of the
CC       bacteria to a coccoid form via the AapA type I TA systems. The peptide
CC       may penetrate the membrane leading to lipid reorganization and thinning
CC       of the bilayer (By similarity). {ECO:0000250|UniProtKB:P0DUM4,
CC       ECO:0000269|PubMed:31411564}.
CC   -!- ACTIVITY REGULATION: Transcription of the aapA3 gene generates a full-
CC       length transcript whose folding impedes translation. Processing of the
CC       3' end of the aapA3 message generates a shorter transcript that becomes
CC       translatable after a structural rearrangement.
CC       {ECO:0000269|PubMed:31411564}.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane
CC       {ECO:0000250|UniProtKB:P0DUM4}.
CC   -!- INDUCTION: Expressed during exponential and stationary growth.
CC       {ECO:0000269|PubMed:31411564}.
CC   -!- SIMILARITY: Belongs to the AapA toxin family. {ECO:0000305}.
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DR   EMBL; AE000511; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   Proteomes; UP000000429; Chromosome.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
PE   1: Evidence at protein level;
KW   Cell inner membrane; Cell membrane; Membrane; Reference proteome;
KW   Stress response; Toxin-antitoxin system.
FT   CHAIN           1..30
FT                   /note="Toxic protein AapA3"
FT                   /id="PRO_0000453285"
FT   MUTAGEN         9
FT                   /note="S->P: No longer toxic."
FT                   /evidence="ECO:0000269|PubMed:31411564"
FT   MUTAGEN         20..30
FT                   /note="Missing: No longer toxic."
FT                   /evidence="ECO:0000269|PubMed:31411564"
SQ   SEQUENCE   30 AA;  3585 MW;  0BC55C58D8B4D82E CRC64;
     MKHKSGKRSW KTLYFEFAFL GLKVIVSVKR