KEGG   ENZYME: 2.4.1.22Help
Entry
EC 2.4.1.22                 Enzyme                                 

Name
lactose synthase;
UDP-galactose---glucose galactosyltransferase;
N-acetyllactosamine synthase;
uridine diphosphogalactose-glucose galactosyltransferase;
lactose synthetase;
UDP-galactose:D-glucose 4-beta-D-galactotransferase;
UDP-galactose:D-glucose 4-beta-D-galactosyltransferase
Class
Transferases;
Glycosyltransferases;
Hexosyltransferases
BRITE hierarchy
Sysname
UDP-alpha-D-galactose:D-glucose 4-beta-D-galactosyltransferase
Reaction(IUBMB)
UDP-alpha-D-galactose + D-glucose = UDP + lactose [RN:R00503 R06067]
Reaction(KEGG)
Substrate
UDP-alpha-D-galactose [CPD:C00052];
D-glucose [CPD:C00031]
Product
UDP [CPD:C00015];
lactose [CPD:C00243]
Comment
The enzyme is a complex of two proteins, A and B. In the absence of the B protein (alpha-lactalbumin), the enzyme catalyses the transfer of galactose from UDP-alpha-D-galactose to N-acetylglucosamine (EC 2.4.1.90 N-acetyllactosamine synthase).
History
EC 2.4.1.22 created 1965
Pathway
ec00052  Galactose metabolism
ec01100  Metabolic pathways
Orthology
K00704  alpha-lactalbumin
K07966  beta-1,4-galactosyltransferase 1
K07967  beta-1,4-galactosyltransferase 2
Genes
HSA: 2683(B4GALT1) 3906(LALBA) 8704(B4GALT2)
PTR: 100613700(B4GALT1) 456522(B4GALT2) 743291(LALBA)
PPS: 100974756(B4GALT1) 100980267(B4GALT2) 100989301(LALBA)
GGO: 101133326(B4GALT2) 101138539(LALBA) 101138982(B4GALT1)
PON: 100437438(LALBA) 100437696(B4GALT2) 100438031(B4GALT1)
NLE: 100583850(LALBA) 100597531(B4GALT1) 100598306(B4GALT2)
MCC: 703541(B4GALT1) 704038(B4GALT2) 707442(LALBA)
MCF: 102115300(B4GALT2) 102131044(B4GALT1) 102146034(LALBA)
CSAB: 103219294(B4GALT1) 103224947(B4GALT2) 103238238(LALBA)
RRO: 104654856(LALBA) 104669045(B4GALT2) 104674271(B4GALT1)
RBB: 108518246(B4GALT1) 108535685(B4GALT2) 108543906(LALBA)
CJC: 100385157(B4GALT1) 100407698(LALBA) 100414763 100896540(B4GALT2)
SBQ: 101038954(LALBA) 101039415(B4GALT2) 101054125(B4GALT1)
MMU: 14595(B4galt1) 16770(Lalba) 53418(B4galt2)
RNO: 24390(B4galt1) 24528(Lalba) 313536(B4galt2)
CGE: 100689430(B4galt1) 100689434(B4galt2) 100758724(Lalba)
NGI: 103741594(B4galt1) 103743868(B4galt2) 103750554(Lalba)
HGL: 101698779 101701591(Lalba) 101718811(B4galt2) 101721414(B4galt1)
CCAN: 109681413 109695495(B4galt2) 109703297(Lalba)
OCU: 100008717(LALBA) 100345726(B4GALT1) 100351419(B4GALT2)
TUP: 102470655(B4GALT1) 102483661(LALBA) 102489782(B4GALT2)
CFA: 403730(LALBA) 481579(B4GALT1) 482527(B4GALT2)
AML: 100471634(B4GALT2) 100477164(B4GALT1) 100478355(LALBA)
UMR: 103667105(B4GALT1) 103670800(B4GALT2) 103675440(LALBA)
ORO: 101362571(B4GALT1) 101364688(B4GALT2) 101376042(LALBA)
FCA: 101084809(B4GALT2) 101090027(LALBA) 101100927(B4GALT1)
PTG: 102955088(B4GALT2) 102959538(B4GALT1) 102972113(LALBA)
AJU: 106969361(LALBA) 106970225(B4GALT2) 106976144(B4GALT1)
BTA: 100125390(B4GALT2) 281781(B4GALT1) 281894(LALBA)
BOM: 102269762(B4GALT1) 102283249(B4GALT2) 102287905(LALBA)
BIU: 109556391(B4GALT2) 109558698(LALBA) 109563168(B4GALT1)
PHD: 102317609(B4GALT2) 102321948(B4GALT1) 102342777(LALBA)
CHX: 100860779(LALBA) 100860927(B4GALT1) 102191101(B4GALT2)
OAS: 100620048(B4GALT1) 101114825(B4GALT2) 443386(LALBA)
SSC: 100511655(B4GALT1) 100736821(B4GALT2) 397647(LALBA)
CFR: 102516080(B4GALT2) 102517623(B4GALT1) 102518569(LALBA)
CDK: 105085573(B4GALT1) 105090897(B4GALT2) 105103818(LALBA)
BACU: 102999260(B4GALT1) 103001417(B4GALT2) 103011536(LALBA)
LVE: 103073762(LALBA) 103086401(B4GALT1) 103086978(B4GALT2)
OOR: 101274354(LALBA) 101285364(B4GALT1) 101285582(B4GALT2)
ECB: 100066149(B4GALT2) 100068209(B4GALT1) 100146585(LALBA)
EPZ: 103548278(B4GALT2) 103555031(B4GALT1) 103563621(LALBA)
EAI: 106836902(LALBA) 106841463(B4GALT1) 106847911(B4GALT2)
MYB: 102240062(B4GALT1) 102248727(B4GALT2) 102251448(LALBA)
MYD: 102751484(B4GALT1) 102768578(LALBA) 102774860(B4GALT2)
HAI: 109371790(B4GALT1) 109383427(B4GALT2) 109393207(LALBA)
RSS: 109443704(LALBA) 109448661(B4GALT1) 109457878(B4GALT2)
PALE: 102878748(B4GALT1) 102884318(B4GALT2) 102892277(LALBA)
LAV: 100657659(B4GALT2) 100659897(B4GALT1) 100677246(LALBA)
MDO: 100010600(B4GALT1) 100024086(LALBA) 100617718(B4GALT2)
SHR: 100918732(B4GALT2) 100929465(B4GALT1) 100931076(LALBA)
OAA: 100075703(B4GALT1) 100092000(B4GALT2)
GGA: 396121(B4GALT1) 396122(B4GALT2)
MGP: 100543545(B4GALT1) 100543680(B4GALT2)
CJO: 107306674(B4GALT1) 107317480(B4GALT2)
APLA: 101792817(B4GALT1) 101802590(B4GALT2)
ACYG: 106040136(B4GALT1) 106049039(B4GALT2)
TGU: 100223650(B4GALT1) 100230857(B4GALT2)
GFR: 102036032(B4GALT2) 102041517(B4GALT1)
FAB: 101805871(B4GALT2) 101807052(B4GALT1)
PHI: 102106294(B4GALT2) 102109081(B4GALT1)
PMAJ: 107198186(B4GALT1) 107208264(B4GALT2)
CCW: 104689823(B4GALT1) 104695261(B4GALT2)
FPG: 101916596(B4GALT2) 101918852(B4GALT1)
FCH: 102046112(B4GALT1) 102056545(B4GALT2)
CLV: 102088289(B4GALT1) 102088677(B4GALT2)
EGZ: 104123065(B4GALT1) 104125508(B4GALT2)
AAM: 106484931(B4GALT2) 106486901(B4GALT1)
ASN: 102372956(B4GALT1) 102376584(B4GALT2)
AMJ: 102558168(B4GALT2) 102559129(B4GALT1)
PSS: 102459690(B4GALT1)
CMY: 102941864(B4GALT2) 102942662(B4GALT1)
CPIC: 101932379(B4GALT1) 101945883(B4GALT2)
ACS: 100557558(b4galt2) 100561064(b4galt1)
PVT: 110073738(B4GALT2) 110087350(B4GALT1)
PBI: 103065477(B4GALT1) 103068203(B4GALT2)
GJA: 107110573(B4GALT1) 107120293(B4GALT2)
XLA: 100190782(b4galt2.S) 108704693 108706812(b4galt1.1.S) 108706813(b4galt1.2.S) 108712215(b4galt1.1.L) 108712216(b4galt1.2.L) 108712940 108712957 108714282(b4galt2.L)
XTR: 100145518(b4galt1.1) 100485024 100492356(b4galt2) 549418(b4galt1.2)
DRE: 100148828(b4galt2) 550425(b4galt1) 768123(b4galt1l)
IPU: 108260689 108267387(b4galt2) 108277608(B4galt1)
AMEX: 103028729 103033307(b4galt2) 103039461
LCO: 104917723(b4galt2) 104938299(b4galt1) 109137286 109141527
NCC: 104941447 104948903(b4galt2)
OLA: 100301598(b4galt2) 101171148(b4galt1)
CSEM: 103376904 103383889 103390794(b4galt1) 103396367(b4galt2)
LCF: 108879172 108883305(b4galt2) 108885296(b4galt1) 108900792
HCQ: 109508336 109524074(b4galt2)
BPEC: 110161009 110164179(b4galt2) 110168019(b4galt1)
LCM: 102350195(B4GALT2) 102357329
CIN: 100175041
BMOR: 101738885
PMAC: 106710215
PXY: 105398071
FCD: 110842915
TUT: 107361940
BMY: Bm1_02765
ADF: 107350754
 » show all
Taxonomy
Reference
1  [PMID:5440844]
  Authors
Fitzgerald DK, Brodbeck U, Kiyosawa I, Mawal R, Colvin B, Ebner KE.
  Title
Alpha-lactalbumin and the lactose synthetase reaction.
  Journal
J Biol Chem 245:2103-8 (1970)
Reference
2  [PMID:812340]
  Authors
Hill RL, Brew K.
  Title
Lactose synthetase.
  Journal
Adv Enzymol Relat Areas Mol Biol 43:411-90 (1975)
Reference
3  [PMID:14005251]
  Authors
WATKINS WM, HASSID WZ.
  Title
The synthesis of lactose by particulate enzyme preparations from guinea pig and bovine mammary glands.
  Journal
J Biol Chem 237:1432-40 (1962)
Other DBs
ExplorEnz - The Enzyme Database: 2.4.1.22
IUBMB Enzyme Nomenclature: 2.4.1.22
ExPASy - ENZYME nomenclature database: 2.4.1.22
BRENDA, the Enzyme Database: 2.4.1.22
CAS: 9030-11-9

DBGET integrated database retrieval system