View source for 1nqi

{{STRUCTURE_1nqi|  PDB=1nqi  |  SCENE=  }} 
===crystal structure of lactose synthase, a 1:1 complex between beta1,4-galactosyltransferase and alpha-lactalbumin in the presence of GlcNAc===
{{ABSTRACT_PUBMED_11419947}}

==Function==
[[http://www.uniprot.org/uniprot/LALBA_MOUSE LALBA_MOUSE]] Regulatory subunit of lactose synthase, changes the substrate specificity of galactosyltransferase in the mammary gland making glucose a good acceptor substrate for this enzyme. This enables LS to synthesize lactose, the major carbohydrate component of milk. In other tissues, galactosyltransferase transfers galactose onto the N-acetylglucosamine of the oligosaccharide chains in glycoproteins. [[http://www.uniprot.org/uniprot/B4GT1_BOVIN B4GT1_BOVIN]] The Golgi complex form catalyzes the production of lactose in the lactating mammary gland and could also be responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids.  The cell surface form functions as a recognition molecule during a variety of cell to cell and cell to matrix interactions, as those occurring during development and egg fertilization, by binding to specific oligosaccharide ligands on opposing cells or in the extracellular matrix. 

==About this Structure==
[[1nqi]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1j92 1j92]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NQI OCA]. 

==See Also==
*[[Glycosyltransferase|Glycosyltransferase]]
*[[Lactalbumin|Lactalbumin]]

==Reference==
<ref group="xtra">PMID:011419947</ref><references group="xtra"/><references/>
[[Category: Bos taurus]]
[[Category: Mus musculus]]
[[Category: Qasba, P K.]]
[[Category: Ramakrishnan, B.]]
[[Category: Lactose synthase]]
[[Category: N-acetylglucosamine binding]]
[[Category: Transferase activator-transferase complex]]