ID   IBP_NOSSH               Reviewed;         269 AA.
AC   A0A7D5JNZ7;
DT   07-APR-2021, integrated into UniProtKB/Swiss-Prot.
DT   02-DEC-2020, sequence version 1.
DT   25-MAY-2022, entry version 6.
DE   RecName: Full=Ice-binding protein {ECO:0000303|PubMed:33158891};
DE            Short=nIBP {ECO:0000303|PubMed:33158891};
DE   Flags: Precursor;
OS   Nostoc sp. (strain HG1).
OC   Bacteria; Cyanobacteria; Nostocales; Nostocaceae; Nostoc.
OX   NCBI_TaxID=2593659;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, SUBCELLULAR LOCATION, DOMAIN,
RP   AND MUTAGENESIS OF 239-VAL--TRP-269.
RX   PubMed=33158891; DOI=10.1128/aem.02499-20;
RA   Raymond J.A., Janech M.G., Mangiagalli M.;
RT   "Ice-Binding Proteins Associated with an Antarctic Cyanobacterium, Nostoc
RT   sp. HG1.";
RL   Appl. Environ. Microbiol. 87:0-0(2021).
CC   -!- FUNCTION: A probable ice-binding protein that has ice-structuring
CC       activities in vitro. Thought not to anchor the cyanobacterium to ice
CC       surfaces, as its habitat is shallow puddles fed by glacier meltwater.
CC       {ECO:0000305|PubMed:33158891}.
CC   -!- SUBCELLULAR LOCATION: Cell outer membrane
CC       {ECO:0000305|PubMed:33158891}; Single-pass membrane protein
CC       {ECO:0000255}. Note=An ice-binding activity is found in the supernatant
CC       and on the surface of clumps of these cells. Only about 80% of the
CC       cells are this strain of Nostoc, so other proteins may be contributing
CC       to ice binding. Probably anchored to the outer membrane by its PEP C-
CC       terminal signal. {ECO:0000305|PubMed:33158891}.
CC   -!- DOMAIN: The ice-binding site may be formed by 7 T/S-X-T motifs.
CC       {ECO:0000305|PubMed:33158891}.
CC   -!- SIMILARITY: Belongs to the ice-binding protein family. {ECO:0000305}.
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; MN082380; QLF98912.1; -; Genomic_DNA.
DR   AlphaFoldDB; A0A7D5JNZ7; -.
DR   SMR; A0A7D5JNZ7; -.
DR   GO; GO:0009279; C:cell outer membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   InterPro; IPR021884; Ice-bd_prot.
DR   InterPro; IPR013424; PEP_exosort_dom.
DR   Pfam; PF11999; Ice_binding; 1.
DR   Pfam; PF07589; PEP-CTERM; 1.
PE   1: Evidence at protein level;
KW   Cell outer membrane; Membrane; Signal; Transmembrane; Transmembrane helix.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000255"
FT   CHAIN           25..269
FT                   /note="Ice-binding protein"
FT                   /evidence="ECO:0000255"
FT                   /id="PRO_5027728693"
FT   TRANSMEM        245..261
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   REGION          240..263
FT                   /note="PEP C-terminal anchor"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           45..47
FT                   /note="Probable ice-binding motif (T/S-X-T) 1"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           65..67
FT                   /note="Probable ice-binding motif (T/S-X-T) 2"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           128..130
FT                   /note="Probable ice-binding motif (T/S-X-T) 3"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           154..156
FT                   /note="Probable ice-binding motif (T/S-X-T) 4"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           180..182
FT                   /note="Probable ice-binding motif (T/S-X-T) 5"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           198..200
FT                   /note="Probable ice-binding motif (T/S-X-T) 6"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MOTIF           218..220
FT                   /note="Probable ice-binding motif (T/S-X-T) 7"
FT                   /evidence="ECO:0000305|PubMed:33158891"
FT   MUTAGEN         239..269
FT                   /note="Missing: Protein still structures ice in vitro."
FT                   /evidence="ECO:0000269|PubMed:33158891"
SQ   SEQUENCE   269 AA;  27596 MW;  D61EB4DDB62D733C CRC64;
     MLKINRKYAI ILAIVAFSSF QTEAKAASIS MLGTASNFGV LGGSTVTNTG PSVITESLGV
     STGSSATGFP PAIVNGTIFT SDTVAAQAQV DNATAYNKLA SLIPNKDLTG LDLGGLTLTP
     GVYSFSSSAQ LTGILTLDNL GDPNALFVFQ IGSTLTTASN SSIVTTNGDA PNVFFQIGSS
     ATLGTGTQFM GNILALTSIT LTTGVNIDCG RALAQNGAVT MDTNKVSNAC YTKPQEKAVV
     PEPDSSLAVL GSGLVSLLFA FRKRFRKGW