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Identification
HMDB Protein ID HMDBP00365
Secondary Accession Numbers
  • 5601
  • HMDBP04834
Name Lactase-phlorizin hydrolase
Synonyms
  1. Lactase
  2. Lactase-glycosylceramidase
  3. Phlorizin hydrolase
Gene Name LCT
Protein Type Enzyme
Biological Properties
General Function Involved in hydrolase activity, hydrolyzing O-glycosyl compounds
Specific Function LPH splits lactose in the small intestine.
Pathways
  • Carbohydrate digestion and absorption
  • Galactose metabolism
  • Galactose Metabolism
  • Galactosemia
  • Lactose Degradation
  • Lactose Intolerance
  • Pyruvaldehyde Degradation
Reactions
beta-Lactose + Water → Beta-D-Galactose + D-Glucose details
Glycosyl-N-acylsphingosine + Water → N-acylsphingosine + a sugar details
beta-Lactose + Water → Alpha-D-Glucose + Beta-D-Galactose details
Lactose + Water → D-Glucose + Beta-D-Galactose details
GO Classification
Biological Process
small molecule metabolic process
response to drug
response to ethanol
response to nutrient
response to starvation
response to nickel cation
polysaccharide digestion
response to sucrose stimulus
response to lead ion
response to hypoxia
carbohydrate metabolic process
response to estrogen stimulus
Cellular Component
brush border
apical plasma membrane
integral to plasma membrane
Function
ion binding
cation binding
binding
catalytic activity
hydrolase activity
hydrolase activity, acting on glycosyl bonds
hydrolase activity, hydrolyzing o-glycosyl compounds
Molecular Function
transferase activity
cation binding
lactase activity
glycosylceramidase activity
Process
metabolic process
primary metabolic process
carbohydrate metabolic process
Cellular Location
  1. Single-pass type I membrane protein
  2. Apical cell membrane
Gene Properties
Chromosome Location 2
Locus 2q21
SNPs LCT
Gene Sequence
>5784 bp
ATGGAGCTGTCTTGGCATGTAGTCTTTATTGCCCTGCTAAGTTTTTCATGCTGGGGGTCA
GACTGGGAGTCTGATAGAAATTTCATTTCCACCGCTGGTCCTCTAACCAATGACTTGCTG
CACAACCTGAGTGGTCTCCTGGGAGACCAGAGTTCTAACTTTGTAGCAGGGGACAAAGAC
ATGTATGTTTGTCACCAGCCACTGCCCACTTTCCTGCCAGAATACTTCAGCAGTCTCCAT
GCCAGTCAGATCACCCATTATAAGGTATTTCTGTCATGGGCACAGCTCCTCCCAGCAGGA
AGCACCCAGAATCCAGACGAGAAAACAGTGCAGTGCTACCGGCGACTCCTCAAGGCCCTC
AAGACTGCACGGCTTCAGCCCATGGTCATCCTGCACCACCAGACCCTCCCTGCCAGCACC
CTCCGGAGAACCGAAGCCTTTGCTGACCTCTTCGCCGACTATGCCACATTCGCCTTCCAC
TCCTTCGGGGACCTAGTTGGGATCTGGTTCACCTTCAGTGACTTGGAGGAAGTGATCAAG
GAGCTTCCCCACCAGGAATCAAGAGCGTCACAACTCCAGACCCTCAGTGATGCCCACAGA
AAAGCCTATGAGATTTACCACGAAAGCTATGCTTTTCAGGGCGGAAAACTCTCTGTTGTC
CTGCGAGCTGAAGATATCCCGGAGCTCCTGCTAGAACCACCCATATCTGCGCTTGCCCAG
GACACGGTCGATTTCCTCTCTCTTGATTTGTCTTATGAATGCCAAAATGAGGCAAGTCTG
CGGCAGAAGCTGAGTAAATTGCAGACCATTGAGCCAAAAGTGAAAGTTTTCATCTTCAAC
CTAAAACTCCCAGACTGCCCCTCCACCATGAAGAACCCAGCCAGTCTGCTCTTCAGCCTT
TTTGAAGCCATAAATAAAGACCAAGTGCTCACCATTGGGTTTGATATTAATGAGTTTCTG
AGTTGTTCATCAAGTTCCAAGAAAAGCATGTCTTGTTCTCTGACTGGCAGCCTGGCCCTT
CAGCCTGACCAGCAGCAGGACCACGAGACCACGGACTCCTCTCCTGCCTCTGCCTATCAG
AGAGTCTGGGAAGCATTTGCCAATCAGTCCAGAGCGGAAAGGGATGCCTTCCTGCAGGAT
ACTTTCCCTGAAGGCTTCCTCTGGGGTGCCTCCACAGGAGCCTTTAACGTGGAAGGAGGC
TGGGCCGAGGGTGGGAGAGGGGTGAGCATCTGGGATCCACGCAGGCCCCTGAACACCACT
GAGGGCCAAGCGACGCTGGAGGTGGCCAGCGACAGTTACCACAAGGTAGCCTCTGACGTC
GCCCTGCTTTGCGGCCTCCGGGCTCAGGTGTACAAGTTCTCCATCTCCTGGTCCCGGATC
TTCCCCATGGGGCACGGGAGCAGCCCCAGCCTCCCAGGCGTTGCCTACTACAACAAGCTG
ATTGACAGGCTACAGGATGCGGGCATCGAGCCCATGGCCACGCTGTTCCACTGGGACCTG
CCTCAGGCCCTGCAGGATCATGGTGGATGGCAGAATGAGAGCGTGGTGGATGCCTTCCTG
GACTATGCGGCCTTCTGCTTCTCCACATTTGGGGACCGTGTGAAGCTGTGGGTGACCTTC
CATGAGCCGTGGGTGATGAGCTACGCAGGCTATGGCACCGGCCAGCACCCTCCCGGCATC
TCTGACCCAGGAGTGGCCTCTTTTAAGGTGGCTCACTTGGTCCTCAAGGCTCATGCCAGA
ACTTGGCACCACTACAACAGCCATCATCGCCCACAGCAGCAGGGGCACGTGGGCATTGTG
CTGAACTCAGACTGGGCAGAACCCCTGTCTCCAGAGAGGCCTGAGGACCTGAGAGCCTCT
GAGCGCTTCTTGCACTTCATGCTGGGCTGGTTTGCACACCCCGTCTTTGTGGATGGAGAC
TACCCAGCCACCCTGAGGACCCAGATCCAACAGATGAACAGACAGTGCTCCCATCCTGTG
GCTCAACTCCCCGAGTTCACAGAGGCAGAGAAGCAGCTCCTGAAAGGCTCTGCTGATTTT
CTGGGTCTGTCGCATTACACCTCCCGCCTCATCAGCAACGCCCCACAAAACACCTGCATC
CCTAGCTATGATACCATTGGAGGCTTCTCCCAACACGTGAACCATGTGTGGCCCCAGACC
TCATCCTCTTGGATTCGTGTGGTGCCCTGGGGGATAAGGAGGCTGTTGCAGTTTGTATCC
CTGGAATACACAAGAGGAAAAGTTCCAATATACCTTGCCGGGAATGGCATGCCCATAGGG
GAAAGTGAAAATCTCTTTGATGATTCCTTAAGAGTAGACTACTTCAATCAATATATCAAT
GAGGTGCTCAAGGCTATCAAGGAAGACTCTGTGGATGTTCGTTCCTACATTGCTCGTTCC
CTCATTGATGGCTTCGAAGGCCCTTCTGGTTACAGCCAGCGGTTTGGCCTGCACCACGTC
AACTTCAGCGACAGCAGCAAGTCAAGGACTCCCAGGAAATCTGCCTACTTTTTCACTAGC
ATCATAGAAAAGAACGGTTTCCTCACCAAGGGGGCAAAAAGACTGCTACCACCTAATACA
GTAAACCTCCCCTCCAAAGTCAGAGCCTTCACTTTTCCATCTGAGGTGCCCTCCAAGGCT
AAAGTCGTTTGGGAAAAGTTCTCCAGCCAACCCAAGTTCGAAAGAGATTTGTTCTACCAC
GGGACGTTTCGGGATGACTTTCTGTGGGGCGTGTCCTCTTCCGCTTATCAGATTGAAGGC
GCGTGGGATGCCGATGGCAAAGGCCCCAGCATCTGGGATAACTTTACCCACACACCAGGG
AGCAATGTGAAAGACAATGCCACTGGAGACATCGCCTGTGACAGCTATCACCAGCTGGAT
GCCGATCTGAATATGCTCCGAGCTTTGAAGGTGAAGGCCTACCGCTTCTCTATCTCCTGG
TCTCGGATTTTCCCAACTGGGAGAAACAGCTCTATCAACAGTCATGGGGTTGATTATTAC
AACAGGCTGATCAATGGCTTGGTGGCAAGCAACATCTTTCCCATGGTGACATTGTTCCAT
TGGGACCTGCCCCAGGCCCTCCAGGATATCGGAGGCTGGGAGAATCCTGCCTTGATTGAC
TTGTTTGACAGCTACGCAGACTTTTGTTTCCAGACCTTTGGTGATAGAGTCAAGTTTTGG
ATGACTTTTAATGAGCCCATGTACCTGGCATGGCTAGGTTATGGCTCAGGGGAATTTCCC
CCAGGGGTGAAGGACCCAGGCTGGGCACCATATAGGATAGCCCACACCGTCATCAAAGCC
CATGCCAGAGTCTATCACACGTACGATGAGAAATACAGGCAGGAGCAGAAGGGGGTCATC
TCGCTGAGCCTCAGTACACACTGGGCAGAGCCCAAGTCACCAGGGGTCCCCAGAGATGTG
GAAGCCGCTGACCGAATGCTGCAGTTCTCCCTGGGCTGGTTTGCTCACCCCATTTTTAGA
AACGGAGACTATCCTGACACCATGAAGTGGAAAGTGGGGAACAGGAGTGAACTGCAGCAC
TTAGCCACCTCCCGCCTGCCAAGCTTCACTGAGGAAGAGAAGAGGTTCATCAGGGCGACG
GCCGACGTCTTCTGCCTCAACACGTACTACTCCAGAATCGTGCAGCACAAAACACCCAGG
CTAAACCCACCCTCCTACGAAGACGACCAGGAGATGGCTGAGGAGGAGGACCCTTCGTGG
CCTTCCACGGCAATGAACAGAGCTGCGCCCTGGGGGACGCGAAGGCTGCTGAACTGGATC
AAGGAAGAGTATGGTGACATCCCCATTTACATCACCGAAAACGGAGTGGGGCTGACCAAT
CCGAACACGGAGGATACTGATAGGATATTTTACCACAAAACCTACATCAATGAGGCTTTG
AAAGCCTACAGGCTCGATGGTATAGACCTTCGAGGGTATGTCGCCTGGTCTCTGATGGAC
AACTTTGAGTGGCTAAATGGCTACACGGTCAAGTTTGGACTGTACCATGTTGATTTCAAC
AACACGAACAGGCCTCGCACAGCAAGAGCCTCCGCCAGGTACTACACAGAGGTCATTACC
AACAACGGCATGCCACTGGCCAGGGAGGATGAGTTTCTGTACGGACGGTTTCCTGAGGGC
TTCATCTGGAGTGCAGCTTCTGCTGCATATCAGATTGAAGGTGCGTGGAGAGCAGATGGC
AAAGGACTCAGCATTTGGGACACGTTTTCTCACACACCACTGAGGGTTGAGAACGATGCC
ATTGGAGACGTGGCCTGTGACAGTTATCACAAGATTGCTGAGGATCTGGTCACCCTGCAG
AACCTGGGTGTGTCCCACTACCGTTTTTCCATCTCCTGGTCTCGCATCCTCCCTGATGGA
ACCACCAGGTACATCAATGAAGCGGGCCTGAACTACTACGTGAGGCTCATCGATACACTG
CTGGCCGCCAGCATCCAGCCCCAGGTGACCATTTACCACTGGGACCTACCACAGACGCTC
CAAGATGTAGGAGGCTGGGAGAATGAGACCATCGTGCAGCGGTTTAAGGAGTATGCAGAT
GTGCTCTTCCAGAGGCTGGGAGACAAGGTGAAGTTTTGGATCACGTTGAATGAGCCCTTT
GTCATTGCTTACCAGGGCTATGGCTACGGAACAGCAGCTCCAGGAGTCTCCAATAGGCCT
GGCACTGCCCCCTACATTGTTGGCCACAATCTAATAAAGGCTCATGCTGAGGCCTGGCAT
CTGTACAACGATGTGTACCGCGCCAGTCAAGGTGGCGTGATTTCCATCACCATCAGCAGT
GACTGGGCTGAACCCAGAGATCCCTCTAACCAGGAGGATGTGGAGGCAGCCAGGAGATAT
GTTCAGTTCATGGGAGGCTGGTTTGCACATCCTATTTTCAAGAATGGAGATTACAATGAG
GTGATGAAGACGCGGATCCGTGACAGGAGCTTGGCTGCAGGCCTCAACAAGTCTCGGCTG
CCAGAATTTACAGAGAGTGAGAAGAGGAGGATCAACGGCACCTATGACTTTTTTGGGTTC
AATCACTACACCACTGTCCTCGCCTACAACCTCAACTATGCCACTGCCATCTCTTCTTTT
GATGCAGACAGAGGAGTTGCTTCCATCGCAGATCGCTCGTGGCCAGACTCTGGCTCCTTC
TGGCTGAAGATGACGCCTTTTGGCTTCAGGAGGATCCTGAACTGGTTAAAGGAGGAATAC
AATGACCCTCCAATTTATGTCACAGAGAATGGAGTGTCCCAGCGGGAAGAAACAGACCTC
AATGACACTGCAAGGATCTACTACCTTCGGACTTACATCAATGAGGCCCTCAAAGCTGTG
CAGGACAAGGTGGACCTTCGAGGATACACAGTTTGGAGTGCGATGGACAATTTTGAGTGG
GCCACAGGCTTTTCAGAGAGATTTGGTCTGCATTTTGTGAACTACAGTGACCCTTCTCTG
CCAAGGATCCCCAAAGCATCAGCGAAGTTCTACGCCTCTGTGGTCCGATGCAATGGCTTC
CCTGACCCCGCTACAGGGCCTCACGCTTGTCTCCACCAGCCAGATGCTGGACCCACCATC
AGCCCCGTGAGACAGGAGGAGGTGCAGTTCCTGGGGCTAATGCTCGGCACCACAGAAGCA
CAGACAGCTTTGTACGTTCTCTTTTCTCTTGTGCTTCTTGGAGTCTGTGGCTTGGCATTT
CTGTCATACAAGTACTGCAAGCGCTCTAAGCAAGGGAAAACACAACGAAGCCAACAGGAA
TTGAGCCCGGTGTCTTCATTCTGA
Protein Properties
Number of Residues 1927
Molecular Weight 218584.77
Theoretical pI 6.344
Pfam Domain Function
Signals Not Available
Transmembrane Regions Not Available
Protein Sequence
>Lactase-phlorizin hydrolase
MELSWHVVFIALLSFSCWGSDWESDRNFISTAGPLTNDLLHNLSGLLGDQSSNFVAGDKD
MYVCHQPLPTFLPEYFSSLHASQITHYKVFLSWAQLLPAGSTQNPDEKTVQCYRRLLKAL
KTARLQPMVILHHQTLPASTLRRTEAFADLFADYATFAFHSFGDLVGIWFTFSDLEEVIK
ELPHQESRASQLQTLSDAHRKAYEIYHESYAFQGGKLSVVLRAEDIPELLLEPPISALAQ
DTVDFLSLDLSYECQNEASLRQKLSKLQTIEPKVKVFIFNLKLPDCPSTMKNPASLLFSL
FEAINKDQVLTIGFDINEFLSCSSSSKKSMSCSLTGSLALQPDQQQDHETTDSSPASAYQ
RVWEAFANQSRAERDAFLQDTFPEGFLWGASTGAFNVEGGWAEGGRGVSIWDPRRPLNTT
EGQATLEVASDSYHKVASDVALLCGLRAQVYKFSISWSRIFPMGHGSSPSLPGVAYYNKL
IDRLQDAGIEPMATLFHWDLPQALQDHGGWQNESVVDAFLDYAAFCFSTFGDRVKLWVTF
HEPWVMSYAGYGTGQHPPGISDPGVASFKVAHLVLKAHARTWHHYNSHHRPQQQGHVGIV
LNSDWAEPLSPERPEDLRASERFLHFMLGWFAHPVFVDGDYPATLRTQIQQMNRQCSHPV
AQLPEFTEAEKQLLKGSADFLGLSHYTSRLISNAPQNTCIPSYDTIGGFSQHVNHVWPQT
SSSWIRVVPWGIRRLLQFVSLEYTRGKVPIYLAGNGMPIGESENLFDDSLRVDYFNQYIN
EVLKAIKEDSVDVRSYIARSLIDGFEGPSGYSQRFGLHHVNFSDSSKSRTPRKSAYFFTS
IIEKNGFLTKGAKRLLPPNTVNLPSKVRAFTFPSEVPSKAKVVWEKFSSQPKFERDLFYH
GTFRDDFLWGVSSSAYQIEGAWDADGKGPSIWDNFTHTPGSNVKDNATGDIACDSYHQLD
ADLNMLRALKVKAYRFSISWSRIFPTGRNSSINSHGVDYYNRLINGLVASNIFPMVTLFH
WDLPQALQDIGGWENPALIDLFDSYADFCFQTFGDRVKFWMTFNEPMYLAWLGYGSGEFP
PGVKDPGWAPYRIAHAVIKAHARVYHTYDEKYRQEQKGVISLSLSTHWAEPKSPGVPRDV
EAADRMLQFSLGWFAHPIFRNGDYPDTMKWKVGNRSELQHLATSRLPSFTEEEKRFIRAT
ADVFCLNTYYSRIVQHKTPRLNPPSYEDDQEMAEEEDPSWPSTAMNRAAPWGTRRLLNWI
KEEYGDIPIYITENGVGLTNPNTEDTDRIFYHKTYINEALKAYRLDGIDLRGYVAWSLMD
NFEWLNGYTVKFGLYHVDFNNTNRPRTARASARYYTEVITNNGMPLAREDEFLYGRFPEG
FIWSAASAAYQIEGAWRADGKGLSIWDTFSHTPLRVENDAIGDVACDSYHKIAEDLVTLQ
NLGVSHYRFSISWSRILPDGTTRYINEAGLNYYVRLIDTLLAASIQPQVTIYHWDLPQTL
QDVGGWENETIVQRFKEYADVLFQRLGDKVKFWITLNEPFVIAYQGYGYGTAAPGVSNRP
GTAPYIVGHNLIKAHAEAWHLYNDVYRASQGGVISITISSDWAEPRDPSNQEDVEAARRY
VQFMGGWFAHPIFKNGDYNEVMKTRIRDRSLAAGLNKSRLPEFTESEKRRINGTYDFFGF
NHYTTVLAYNLNYATAISSFDADRGVASIADRSWPDSGSFWLKMTPFGFRRILNWLKEEY
NDPPIYVTENGVSQREETDLNDTARIYYLRTYINEALKAVQDKVDLRGYTVWSAMDNFEW
ATGFSERFGLHFVNYSDPSLPRIPKASAKFYASVVRCNGFPDPATGPHACLHQPDAGPTI
SPVRQEEVQFLGLMLGTTEAQTALYVLFSLVLLGVCGLAFLSYKYCKRSKQGKTQRSQQE
LSPVSSF
GenBank ID Protein 34400
UniProtKB/Swiss-Prot ID P09848
UniProtKB/Swiss-Prot Entry Name LPH_HUMAN
PDB IDs Not Available
GenBank Gene ID X07994
GeneCard ID LCT
GenAtlas ID LCT
HGNC ID HGNC:6530
References
General References
  1. Hillier LW, Graves TA, Fulton RS, Fulton LA, Pepin KH, Minx P, Wagner-McPherson C, Layman D, Wylie K, Sekhon M, Becker MC, Fewell GA, Delehaunty KD, Miner TL, Nash WE, Kremitzki C, Oddy L, Du H, Sun H, Bradshaw-Cordum H, Ali J, Carter J, Cordes M, Harris A, Isak A, van Brunt A, Nguyen C, Du F, Courtney L, Kalicki J, Ozersky P, Abbott S, Armstrong J, Belter EA, Caruso L, Cedroni M, Cotton M, Davidson T, Desai A, Elliott G, Erb T, Fronick C, Gaige T, Haakenson W, Haglund K, Holmes A, Harkins R, Kim K, Kruchowski SS, Strong CM, Grewal N, Goyea E, Hou S, Levy A, Martinka S, Mead K, McLellan MD, Meyer R, Randall-Maher J, Tomlinson C, Dauphin-Kohlberg S, Kozlowicz-Reilly A, Shah N, Swearengen-Shahid S, Snider J, Strong JT, Thompson J, Yoakum M, Leonard S, Pearman C, Trani L, Radionenko M, Waligorski JE, Wang C, Rock SM, Tin-Wollam AM, Maupin R, Latreille P, Wendl MC, Yang SP, Pohl C, Wallis JW, Spieth J, Bieri TA, Berkowicz N, Nelson JO, Osborne J, Ding L, Meyer R, Sabo A, Shotland Y, Sinha P, Wohldmann PE, Cook LL, Hickenbotham MT, Eldred J, Williams D, Jones TA, She X, Ciccarelli FD, Izaurralde E, Taylor J, Schmutz J, Myers RM, Cox DR, Huang X, McPherson JD, Mardis ER, Clifton SW, Warren WC, Chinwalla AT, Eddy SR, Marra MA, Ovcharenko I, Furey TS, Miller W, Eichler EE, Bork P, Suyama M, Torrents D, Waterston RH, Wilson RK: Generation and annotation of the DNA sequences of human chromosomes 2 and 4. Nature. 2005 Apr 7;434(7034):724-31. [PubMed:15815621 ]
  2. Wang Y, Du D, Fang L, Yang G, Zhang C, Zeng R, Ullrich A, Lottspeich F, Chen Z: Tyrosine phosphorylated Par3 regulates epithelial tight junction assembly promoted by EGFR signaling. EMBO J. 2006 Nov 1;25(21):5058-70. Epub 2006 Oct 19. [PubMed:17053785 ]
  3. Mantei N, Villa M, Enzler T, Wacker H, Boll W, James P, Hunziker W, Semenza G: Complete primary structure of human and rabbit lactase-phlorizin hydrolase: implications for biosynthesis, membrane anchoring and evolution of the enzyme. EMBO J. 1988 Sep;7(9):2705-13. [PubMed:2460343 ]
  4. Boll W, Wagner P, Mantei N: Structure of the chromosomal gene and cDNAs coding for lactase-phlorizin hydrolase in humans with adult-type hypolactasia or persistence of lactase. Am J Hum Genet. 1991 May;48(5):889-902. [PubMed:1902057 ]
  5. Enattah NS, Sahi T, Savilahti E, Terwilliger JD, Peltonen L, Jarvela I: Identification of a variant associated with adult-type hypolactasia. Nat Genet. 2002 Feb;30(2):233-7. Epub 2002 Jan 14. [PubMed:11788828 ]
  6. Kuokkanen M, Kokkonen J, Enattah NS, Ylisaukko-Oja T, Komu H, Varilo T, Peltonen L, Savilahti E, Jarvela I: Mutations in the translated region of the lactase gene (LCT) underlie congenital lactase deficiency. Am J Hum Genet. 2006 Feb;78(2):339-44. Epub 2005 Dec 15. [PubMed:16400612 ]