ID   SIAP_HAEI8              Reviewed;         329 AA.
AC   Q4QP41;
DT   30-MAY-2006, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2005, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Sialic acid-binding periplasmic protein SiaP;
DE   AltName: Full=Extracytoplasmic solute receptor protein SiaP;
DE   AltName: Full=N-acetylneuraminic-binding protein;
DE   AltName: Full=Neu5Ac-binding protein;
DE   Flags: Precursor;
GN   Name=siaP; OrderedLocusNames=NTHI0232;
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).
CC   -!- FUNCTION: Part of the tripartite ATP-independent periplasmic (TRAP)
CC       transport system SiaPT involved in the uptake of sialic acid (N-acetyl-
CC       beta-neuraminate). This protein specifically binds sialic acid with
CC       high affinity. N-Acetylneuraminate (sialic acid) can then be
CC       incorporated into the lipooligosaccharides (LOS) as a terminal non-
CC       reducing sugar, protecting the bacterium from complement-mediated
CC       killing by normal human serum. {ECO:0000250|UniProtKB:P44542}.
CC   -!- SUBUNIT: The complex comprises the extracytoplasmic solute receptor
CC       protein SiaP, and the fused transmembrane protein SiaT. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the bacterial solute-binding protein 7 family.
CC       {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; CP000057; AAX87206.1; -; Genomic_DNA.
DR   RefSeq; WP_005691499.1; NC_007146.2.
DR   AlphaFoldDB; Q4QP41; -.
DR   SMR; Q4QP41; -.
DR   EnsemblBacteria; AAX87206; AAX87206; NTHI0232.
DR   KEGG; hit:NTHI0232; -.
DR   HOGENOM; CLU_036176_1_1_6; -.
DR   OMA; FTYKYAN; -.
DR   Proteomes; UP000002525; Chromosome.
DR   GO; GO:0030288; C:outer membrane-bounded periplasmic space; IEA:InterPro.
DR   GO; GO:0008643; P:carbohydrate transport; IEA:UniProtKB-KW.
DR   GO; GO:0055085; P:transmembrane transport; IEA:InterPro.
DR   Gene3D; 3.40.190.170; -; 1.
DR   InterPro; IPR018389; DctP_fam.
DR   InterPro; IPR004682; TRAP_DctP.
DR   InterPro; IPR038404; TRAP_DctP_sf.
DR   PANTHER; PTHR33376; PTHR33376; 1.
DR   Pfam; PF03480; DctP; 1.
DR   PIRSF; PIRSF006470; DctB; 1.
DR   TIGRFAMs; TIGR00787; dctP; 1.
PE   3: Inferred from homology;
KW   Periplasm; Signal; Sugar transport; Transport.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000255"
FT   CHAIN           24..329
FT                   /note="Sialic acid-binding periplasmic protein SiaP"
FT                   /id="PRO_0000238448"
FT   BINDING         33
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
FT   BINDING         72
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
FT   BINDING         90
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
FT   BINDING         150
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
FT   BINDING         170
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
FT   BINDING         210
FT                   /ligand="N-acetyl-beta-neuraminate"
FT                   /ligand_id="ChEBI:CHEBI:58705"
FT                   /evidence="ECO:0000250|UniProtKB:P44542"
SQ   SEQUENCE   329 AA;  36439 MW;  4E3688D751DE1FD7 CRC64;
     MMKLTKLFLA TAISLGVSSA VLAADYDLKF GMNAGTSSNE YKAAEMFAKE VKEKSQGKIE
     ISLYPSSQLG DDRAMLKQLK DGSLDFTFAE SARFQLFYPE AAVFALPYVI SNYNVAQKAL
     FDTEFGKDLI KKMDKDLGVT LLSQAYNGTR QTTSNRAINS IADMKGLKLR VPNAATNLAY
     AKYVGASPTP MAFSEVYLAL QTNAVDGQEN PLAAVQAQKF YEVQKFLAMT NHILNDQLYL
     VSNETYKELP EDLQKVVKDA AENAAKYHTK LFVDGEKDLV TFFEKQGVKI THPDLVPFKA
     SMKPYYAEFV KQTGQKGEAA LKQIEAINP