Reaction: B4GALT1:LALBA transfers Gal from UDP-Gal to Glc to form Lac
- in pathway: Lactose synthesis
In the Golgi membrane, the B4GALT1 subunit of the B4GALT1:LALBA (beta-1,4-galactosyltransferase 1 : alpha-lactalbumin) complex catalyzes the transfer of galactose from UDP-galactose to free glucose to form galactose and UDP (Andrews 1970; Ramakrishnan & Qasba 2001). The representation here of a stable protein complex catalyzing the transformation of small molecule substrates provides a simplified view of the true reaction mechanism (Brew and Hill 1975), but is sufficient to identify the key participating molecules and their roles.
Reaction - small molecule participants:
Lac [Golgi lumen]
UDP [Golgi lumen]
UDP-Gal [Golgi lumen]
Glc [Golgi lumen]
Reactome.org reaction link: R-HSA-5653878
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Reaction input - small molecules:
UDP-alpha-D-galactose(2-)
alpha-D-glucose
Reaction output - small molecules:
lactose
UDP(3-)
Reactome.org link: R-HSA-5653878