ID   HGBA_HAEIF              Reviewed;        1013 AA.
AC   Q9KIV2;
DT   29-AUG-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Hemoglobin-binding protein A;
DE   Flags: Precursor;
GN   Name=hgbA;
OS   Haemophilus influenzae.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Pasteurellales;
OC   Pasteurellaceae; Haemophilus.
OX   NCBI_TaxID=727;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=NTHi N182;
RX   PubMed=10858226; DOI=10.1128/iai.68.7.4092-4101.2000;
RA   Cope L.D., Hrkal Z., Hansen E.J.;
RT   "Detection of phase variation in expression of proteins involved in
RT   hemoglobin and hemoglobin-haptoglobin binding by nontypeable Haemophilus
RT   influenzae.";
RL   Infect. Immun. 68:4092-4101(2000).
CC   -!- FUNCTION: Acts as a receptor for hemoglobin of the human host and is
CC       required for heme uptake.
CC   -!- SUBCELLULAR LOCATION: Cell outer membrane.
CC   -!- MISCELLANEOUS: This protein is subject to phase-variable expression
CC       associated with alteration in the length of the CCAA repeat region.
CC       This mechanism is called slipped-strand mispairing. Addition or loss of
CC       CCAA repeat units would change the reading frame and result in
CC       introduction of stop codons downstream of the repeat region. This may
CC       be a mechanism of regulation and a way to avoid the immunological
CC       response of the host.
CC   -!- SIMILARITY: Belongs to the TonB-dependent receptor family.
CC       Hemoglobin/haptoglobin binding protein subfamily. {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; AF221059; AAF80176.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9KIV2; -.
DR   SMR; Q9KIV2; -.
DR   GO; GO:0009279; C:cell outer membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0022857; F:transmembrane transporter activity; IEA:InterPro.
DR   GO; GO:0006811; P:ion transport; IEA:UniProt.
DR   GO; GO:0071702; P:organic substance transport; IEA:UniProt.
DR   Gene3D; 2.170.130.10; -; 1.
DR   Gene3D; 2.40.170.20; -; 2.
DR   InterPro; IPR039426; BtuB-like.
DR   InterPro; IPR012910; Plug_dom.
DR   InterPro; IPR037066; Plug_dom_sf.
DR   InterPro; IPR006970; PT.
DR   InterPro; IPR000531; TonB-dep_rcpt_b-brl.
DR   InterPro; IPR010949; TonB_Hb/transfer/lactofer_rcpt.
DR   InterPro; IPR036942; TonB_rcpt_b-brl_sf.
DR   InterPro; IPR010917; TonB_rcpt_CS.
DR   PANTHER; PTHR30069; PTHR30069; 1.
DR   Pfam; PF07715; Plug; 1.
DR   Pfam; PF04886; PT; 1.
DR   Pfam; PF00593; TonB_dep_Rec; 1.
DR   TIGRFAMs; TIGR01786; TonB-hemlactrns; 1.
DR   PROSITE; PS01156; TONB_DEPENDENT_REC_2; 1.
PE   3: Inferred from homology;
KW   Cell outer membrane; Membrane; Receptor; Repeat; Signal; TonB box;
KW   Transmembrane; Transmembrane beta strand; Transport.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000255"
FT   CHAIN           25..1013
FT                   /note="Hemoglobin-binding protein A"
FT                   /id="PRO_0000034781"
FT   REPEAT          26..29
FT                   /note="1"
FT   REPEAT          30..33
FT                   /note="2"
FT   REPEAT          34..37
FT                   /note="3"
FT   REPEAT          38..41
FT                   /note="4"
FT   REPEAT          42..45
FT                   /note="5"
FT   REPEAT          46..49
FT                   /note="6"
FT   REPEAT          50..53
FT                   /note="7"
FT   REPEAT          54..57
FT                   /note="8"
FT   REGION          26..61
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          26..57
FT                   /note="8 X 4 AA tandem repeats of Q-P-T-N"
FT   MOTIF           67..74
FT                   /note="TonB box"
FT   MOTIF           996..1013
FT                   /note="TonB C-terminal box"
SQ   SEQUENCE   1013 AA;  116261 MW;  769964335A4ED3C1 CRC64;
     MTNFKFSLLA CSIAFALNAS TAYAAQPTNQ PTNQPTNQPT NQPTNQPTNQ PTNQPTNQDS
     NLSEQLEQIN VSGSTENSDS KTPPKIAETV KTAKTLEREQ ANNIKDIVKY ETGVTVVEAG
     RFGQSGFAIR GVDENRVAIN IDGLRQAETL SSQGFKELFE GYGNFNNTRN GAEIETLKEV
     NITKGANSIK SGSGSLGGSV IYKTKDARDY LLNKDYYVSY KKGYATENNQ SFNTLTLAGR
     YKKFDVLVVT TSRNGHELEN YGYKNYNDKI QGKRREKADP YKIEQDSTLL KLSFNPTENH
     RFTLAADLYE HRSRGQDLSY TLKYLKTLPD LPEVDSRHTN DKTKRHNISF SYENFSQTPF
     WDTLKITFSK QKIKTRARTD EYCDAGVRYC EGTANPAGLK LKNGEITRRD GTPLQFKEIN
     NTTTPNSNSN KDKTYDFSKL IDTNGKEIES GITRSNDTFW YDCSIFDCEN PGKMKVAEGK
     TYYRYDGTWK NNVQLEKKVL NGKEFARINN GTRGKTFPIL PSSLGYLERL WQERDLDTNT
     QQLNLDLTKD FKTWRVEHNL QYGSSYNTTM KRMVNRAGYD ATDVQWWAKR TLGTRFDFLK
     NEEIVETCAT TFGWNAFLCP RVDPEFSYLL PIKTKEKSVY LFDNVVITDY LSFDLGYRYD
     NIHYQPKYKH GVTPKLPDDI VKELFIPLKS GQNNNDAEVK KNVQENIDYI AKQNKKYKAH
     SYSFVSTIDP TSFLRLQLKY SKGFRAPTSD EMYFTFKHPD FTILPNTHLK PEIAKTKEIA
     FTLHHDDWGF ISTSLFKTNY RDFIDLVYKG EREFEVGNPN NRGKISFDTF QNINRDSAVV
     KGIEINSKVF LGKMAKFMDG FNLSYKYTYQ KGRMDGNIPM NAIQPKTMVY GLGYDHPSQK
     FGFNFYTTHV ASKNPEDTYD IYAKDKNQTN TSIKWRSKSY TILDLIGYVQ PIKNLTIRAG
     VYNLTNRKYI TWDSARSIRS FGTSNVIDQK TGQGINRFYA PGRNYKMSVQ FEF