Galactose-1-phosphate uridylyltransferase

From Wikipedia, the free encyclopedia

Identifiers

Symbol(s)

GALT;

External IDs

OMIM: 606999 MGI: 95638 HomoloGene: 126

EC number

2.7.7.12

Gene ontology
Molecular Function:	• iron ion binding • UDP-glucose:hexose-1-phosphate uridylyltransferase activity • zinc ion binding • transferase activity • metal ion binding
Biological Process:	• carbohydrate metabolic process • galactose metabolic process

Orthologs

Human

Mouse

n/a

n/a

Refseq

NM_000155 (mRNA)
NP_000146 (protein)

NM_016658 (mRNA)
NP_057867 (protein)

Location

n/a

Chr 4: 41.94 - 41.95 Mb

Pubmed search

[1]

[2]

Galactose-1-phosphate uridyl transferase (or GALT) is an enzyme (EC 2.7.7.12) responsible for converting ingested galactose to glucose.^[1]

Galactose-1-phosphate uridyl transferase (GALT) catalyzes the second step of the Leloir pathway of galactose metabolism, namely the conversion of UDP-glucose + galactose-1-phosphate to glucose-1-phosphate + UDP-galactose. The expression of GALT is controlled by the actions of the FOXO3 gene. The absence of this enzyme results in classic galactosemia in humans and can be fatal in the newborn period if lactose is not removed from the diet. The pathophysiology of galactosemia has not been clearly defined.^[1]

galactose

glucose

More specifically, it creates UDP-galactose and glucose 1-phosphate from UDP-glucose and galactose 1-phosphate.

1 Clinical significance
2 References
3 Further reading
4 External links

[edit] Clinical significance

Deficiency of GALT causes classic galactosemia.

[edit] References

^ ^a ^b Entrez Gene: GALT galactose-1-phosphate uridylyltransferase.

[edit] Further reading

Reichardt JK (1993). "Genetic basis of galactosemia.". Hum. Mutat. 1 (3): 190-6. doi:10.1002/humu.1380010303. PMID 1301925.
Tyfield L, Reichardt J, Fridovich-Keil J, et al. (1999). "Classical galactosemia and mutations at the galactose-1-phosphate uridyl transferase (GALT) gene.". Hum. Mutat. 13 (6): 417-30. doi:10.1002/(SICI)1098-1004(1999)13:6<417::AID-HUMU1>3.0.CO;2-0. PMID 10408771.
Reichardt JK, Belmont JW, Levy HL, Woo SL (1992). "Characterization of two missense mutations in human galactose-1-phosphate uridyltransferase: different molecular mechanisms for galactosemia.". Genomics 12 (3): 596-600. doi:10.1016/0888-7543(92)90453-Y. PMID 1373122.
Leslie ND, Immerman EB, Flach JE, et al. (1992). "The human galactose-1-phosphate uridyltransferase gene.". Genomics 14 (2): 474-80. doi:10.1016/S0888-7543(05)80244-7. PMID 1427861.
Reichardt JK, Levy HL, Woo SL (1992). "Molecular characterization of two galactosemia mutations and one polymorphism: implications for structure-function analysis of human galactose-1-phosphate uridyltransferase.". Biochemistry 31 (24): 5430-3. doi:10.1021/bi00139a002. PMID 1610789.
Reichardt JK, Packman S, Woo SL (1991). "Molecular characterization of two galactosemia mutations: correlation of mutations with highly conserved domains in galactose-1-phosphate uridyl transferase.". Am. J. Hum. Genet. 49 (4): 860-7. PMID 1897530.
Reichardt JK, Woo SL (1991). "Molecular basis of galactosemia: mutations and polymorphisms in the gene encoding human galactose-1-phosphate uridylyltransferase.". Proc. Natl. Acad. Sci. U.S.A. 88 (7): 2633-7. doi:10.1073/pnas.88.7.2633. PMID 2011574.
Flach JE, Reichardt JK, Elsas LJ (1990). "Sequence of a cDNA encoding human galactose-1-phosphate uridyl transferase.". Mol. Biol. Med. 7 (4): 365-9. PMID 2233247.
Reichardt JK, Berg P (1988). "Cloning and characterization of a cDNA encoding human galactose-1-phosphate uridyl transferase.". Mol. Biol. Med. 5 (2): 107-22. PMID 2840550.
Bergren WG, Donnell GN (1974). "A new variant of galactose-1-phosphate uridyltransferase in man: the Los Angeles variant.". Ann. Hum. Genet. 37 (1): 1-8. PMID 4759900.
Shih LY, Suslak L, Rosin I, et al. (1985). "Gene dosage studies supporting localization of the structural gene for galactose-1-phosphate uridyl transferase (GALT) to band p13 of chromosome 9.". Am. J. Med. Genet. 19 (3): 539-43. doi:10.1002/ajmg.1320190316. PMID 6095663.
Ashino J, Okano Y, Suyama I, et al. (1995). "Molecular characterization of galactosemia (type 1) mutations in Japanese.". Hum. Mutat. 6 (1): 36-43. doi:10.1002/humu.1380060108. PMID 7550229.
Elsas LJ, Langley S, Paulk EM, et al. (1995). "A molecular approach to galactosemia.". Eur. J. Pediatr. 154 (7 Suppl 2): S21-7. doi:10.1007/BF02143798. PMID 7671959.
Elsas LJ, Langley S, Steele E, et al. (1995). "Galactosemia: a strategy to identify new biochemical phenotypes and molecular genotypes.". Am. J. Hum. Genet. 56 (3): 630-9. PMID 7887416.
Fridovich-Keil JL, Langley SD, Mazur LA, et al. (1995). "Identification and functional analysis of three distinct mutations in the human galactose-1-phosphate uridyltransferase gene associated with galactosemia in a single family.". Am. J. Hum. Genet. 56 (3): 640-6. PMID 7887417.
Davit-Spraul A, Pourci ML, Ng KH, et al. (1994). "Regulatory effects of galactose on galactose-1-phosphate uridyltransferase activity on human hepatoblastoma HepG2 cells.". FEBS Lett. 354 (2): 232-6. doi:10.1016/0014-5793(94)01133-8. PMID 7957929.
Lin HC, Kirby LT, Ng WG, Reichardt JK (1994). "On the molecular nature of the Duarte variant of galactose-1-phosphate uridyl transferase (GALT).". Hum. Genet. 93 (2): 167-9. doi:10.1007/BF00210604. PMID 8112740.
Elsas LJ, Dembure PP, Langley S, et al. (1994). "A common mutation associated with the Duarte galactosemia allele.". Am. J. Hum. Genet. 54 (6): 1030-6. PMID 8198125.
Reichardt JK, Novelli G, Dallapiccola B (1993). "Molecular characterization of the H319Q galactosemia mutation.". Hum. Mol. Genet. 2 (3): 325-6. doi:10.1093/hmg/2.3.325. PMID 8499924.

[edit] External links

v • d • e Transferases: Phosphotransferases/kinases (EC 2.7)

2.7.1 - OH acceptor	Hexo- - Gluco- - Fructo- (Hepatic fructo-) - Galacto- - Phosphofructo- (1, 2) - Riboflavin - Shikimate - Thymidine - NAD⁺ - Glycerol - Pantothenate - Mevalonate - Pyruvate - Deoxycytidine - PFP - Diacylglycerol - Bruton's tyrosine - Phosphoinositide 3 (Class I PI 3, Class II PI 3) - Sphingosine

2.7.2 - COOH acceptor	Phosphoglycerate - Aspartate

2.7.3 - N acceptor	Creatine

2.7.4 - PO₄ acceptor	Phosphomevalonate - Adenylate - Nucleoside-diphosphate

2.7.6 - P₂O₇	Ribose-phosphate diphosphokinase - Thiamine pyrophosphokinase

2.7.7 - nucleotidyl-	Integrase - PNPase - Polymerase - RNase PH - UDP-glucose pyrophosphorylase - Galactose-1-phosphate uridylyltransferase -Terminal deoxynucleotidyl transferase - RNA replicase - Reverse transcriptase (Telomerase) - Transposase

2.7.8 - other phos.	N-acetylglucosamine-1-phosphate transferase

2.7.10-11 - protein	Tyrosine - Serine/threonine-specific

v • d • e Metabolism: carbohydrate metabolism - fructose and galactose enzymes

Fructose	Hepatic fructokinase - Aldolase B

Sorbitol	Sorbitol dehydrogenase - Aldose reductase

Galactose	Galactokinase - Galactose-1-phosphate uridylyltransferase - UDP galactose epimerase Aldose reductase

Lactose	Lactose synthase - Lactase

see also disorders