ID LACY_CITFR Reviewed; 416 AA.
AC P47234;
DT 01-FEB-1996, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1996, sequence version 1.
DT 27-MAR-2024, entry version 98.
DE RecName: Full=Lactose permease;
DE AltName: Full=Lactose-proton symport;
GN Name=lacY;
OS Citrobacter freundii.
OC Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Citrobacter; Citrobacter freundii complex.
OX NCBI_TaxID=546;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=7945341; DOI=10.1006/bbrc.1994.2407;
RA Lee J.I., Okazaki N., Tsuchiya T., Wilson T.H.;
RT "Cloning and sequencing of the gene for the lactose carrier of Citrobacter
RT freundii.";
RL Biochem. Biophys. Res. Commun. 203:1882-1888(1994).
CC -!- FUNCTION: Responsible for transport of beta-galactosides into the cell,
CC with the concomitant import of a proton (symport system).
CC {ECO:0000250|UniProtKB:P02920}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=H(+)(in) + lactose(in) = H(+)(out) + lactose(out);
CC Xref=Rhea:RHEA:28867, ChEBI:CHEBI:15378, ChEBI:CHEBI:17716;
CC Evidence={ECO:0000250|UniProtKB:P02920};
CC PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:28869;
CC Evidence={ECO:0000250|UniProtKB:P02920};
CC -!- SUBCELLULAR LOCATION: Cell inner membrane
CC {ECO:0000250|UniProtKB:P02920}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P02920}.
CC -!- SIMILARITY: Belongs to the major facilitator superfamily.
CC Oligosaccharide:H(+) symporter (OHS) (TC 2.A.1.5) family.
CC {ECO:0000305}.
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DR EMBL; U13675; AAA61795.1; -; Genomic_DNA.
DR PIR; JC2544; JC2544.
DR AlphaFoldDB; P47234; -.
DR SMR; P47234; -.
DR STRING; 1333848.CFNIH1_11750; -.
DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0005351; F:carbohydrate:proton symporter activity; IEA:InterPro.
DR CDD; cd06172; MFS_LacY; 1.
DR Gene3D; 1.20.1250.20; MFS general substrate transporter like domains; 2.
DR InterPro; IPR000576; LacY/RafB_perm_fam.
DR InterPro; IPR018457; LacY/RafB_perm_fam_CS.
DR InterPro; IPR020846; MFS_dom.
DR InterPro; IPR036259; MFS_trans_sf.
DR NCBIfam; TIGR00882; 2A0105; 1.
DR PANTHER; PTHR23522; BLL5896 PROTEIN; 1.
DR PANTHER; PTHR23522:SF9; LACTOSE PERMEASE-RELATED; 1.
DR Pfam; PF01306; LacY_symp; 1.
DR PRINTS; PR00174; LACYSMPORT.
DR SUPFAM; SSF103473; MFS general substrate transporter; 1.
DR PROSITE; PS00896; LACY_1; 1.
DR PROSITE; PS00897; LACY_2; 1.
DR PROSITE; PS50850; MFS; 1.
PE 3: Inferred from homology;
KW Cell inner membrane; Cell membrane; Membrane; Sugar transport; Symport;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..416
FT /note="Lactose permease"
FT /id="PRO_0000196183"
FT TOPO_DOM 1..13
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 14..34
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 35..45
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 46..66
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 67..75
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 76..96
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 97
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 98..118
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 119..144
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 145..165
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 166
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 167..187
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 188..211
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 212..232
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 233..262
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 263..283
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 284..290
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 291..309
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 310..314
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 315..336
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 337..347
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 348..368
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 369..378
FT /note="Periplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 379..399
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 400..416
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT SITE 126
FT /note="Substrate binding"
FT /evidence="ECO:0000250|UniProtKB:P02920"
FT SITE 144
FT /note="Substrate binding"
FT /evidence="ECO:0000250|UniProtKB:P02920"
FT SITE 269
FT /note="Substrate binding and proton translocation"
FT /evidence="ECO:0000250|UniProtKB:P02920"
FT SITE 302
FT /note="Proton translocation"
FT /evidence="ECO:0000250|UniProtKB:P02920"
FT SITE 321
FT /note="Proton translocation"
FT /evidence="ECO:0000250|UniProtKB:P02920"
FT SITE 324
FT /note="Proton translocation"
FT /evidence="ECO:0000250|UniProtKB:P02920"
SQ SEQUENCE 416 AA; 46537 MW; E64D04FAB69168BB CRC64;
MYYLKNTNFW MFGFFFFFYF FIMGAYFPFF PIWLHEVNHI SKGDTGIIFA CISLFSLLFQ
PIFGLLSDKL GLRKHLLWVI TGMLVMFAPF FIYVFGPLLQ VNILLGSIVG GIYLGFIYNA
GAPAIEAYIE KASRRSNFEF GRARMFGCVG WALCASIAGI MFTINNQFVF WLGSGCAVIL
ALLLLFSKTD VPSSAKVADA VGANNSAFSL KLALELFKQP KLWLISLYVV GVSCTYDVFD
QQFANFFTSF FATGEQGTRV FGYVTTMGEL LNASIMFFAP LIVNRIGGKN ALLLAGTIMS
VRIIGSHSHT ALEVVILKTL HMFEIPFLIV GCFKYITSQF EVRFSATIYL VCFCFFKQLA
MIFMSVLAGK MYESIGFQGA YLVLGIIRVS FTLISVFTLS GPGPFSLLRR RESVAL
//
