4js2: Difference between revisions
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==Crystal structure of human Beta-galactoside alpha-2,6-sialyltransferase 1 in complex with CMP== | ==Crystal structure of human Beta-galactoside alpha-2,6-sialyltransferase 1 in complex with CMP== | ||
<StructureSection load='4js2' size='340' side='right' caption='[[4js2]], [[Resolution|resolution]] 2.30Å' scene=''> | <StructureSection load='4js2' size='340' side='right'caption='[[4js2]], [[Resolution|resolution]] 2.30Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4js2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4JS2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4JS2 FirstGlance]. <br> | <table><tr><td colspan='2'>[[4js2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4JS2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4JS2 FirstGlance]. <br> | ||
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== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/SIAT1_HUMAN SIAT1_HUMAN]] Transfers sialic acid from the donor of substrate CMP-sialic acid to galactose containing acceptor substrates.<ref>PMID:21081508</ref> | [[http://www.uniprot.org/uniprot/SIAT1_HUMAN SIAT1_HUMAN]] Transfers sialic acid from the donor of substrate CMP-sialic acid to galactose containing acceptor substrates.<ref>PMID:21081508</ref> | ||
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== Publication Abstract from PubMed == | |||
Human beta-galactoside alpha-2,6-sialyltransferase I (ST6Gal-I) establishes the final glycosylation pattern of many glycoproteins by transferring a sialyl moiety to a terminal galactose. Complete sialylation of therapeutic immunoglobulins is essential for their anti-inflammatory activity and protein stability, but is difficult to achieve in vitro owing to the limited activity of ST6Gal-I towards some galactose acceptors. No structural information on ST6Gal-I that could help to improve the enzymatic properties of ST6Gal-I for biotechnological purposes is currently available. Here, the crystal structures of human ST6Gal-I in complex with the product cytidine 5'-monophosphate and in complex with cytidine and phosphate are described. These complexes allow the rationalization of the inhibitory activity of cytosine-based nucleotides. ST6Gal-I adopts a variant of the canonical glycosyltransferase A fold and differs from related sialyltransferases by several large insertions and deletions that determine its regiospecificity and substrate specificity. A large glycan from a symmetry mate localizes to the active site of ST6Gal-I in an orientation compatible with catalysis. The glycan binding mode can be generalized to any glycoprotein that is a substrate of ST6Gal-I. Comparison with a bacterial sialyltransferase in complex with a modified sialyl donor lends insight into the Michaelis complex. The results support an SN2 mechanism with inversion of configuration at the sialyl residue and suggest substrate-assisted catalysis with a charge-relay mechanism that bears a conceptual similarity to serine proteases. | |||
The structure of human alpha-2,6-sialyltransferase reveals the binding mode of complex glycans.,Kuhn B, Benz J, Greif M, Engel AM, Sobek H, Rudolph MG Acta Crystallogr D Biol Crystallogr. 2013 Sep;69(Pt 9):1826-38. doi:, 10.1107/S0907444913015412. Epub 2013 Aug 17. PMID:23999306<ref>PMID:23999306</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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<div class="pdbe-citations 4js2" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Sialyltransferase|Sialyltransferase]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
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[[Category: Beta-galactoside alpha-2,6-sialyltransferase]] | [[Category: Beta-galactoside alpha-2,6-sialyltransferase]] | ||
[[Category: Human]] | [[Category: Human]] | ||
[[Category: Large Structures]] | |||
[[Category: Benz, J]] | [[Category: Benz, J]] | ||
[[Category: Engel, A M]] | [[Category: Engel, A M]] | ||