1q22: Difference between revisions

[[Image:1q22.gif|left|200px]]<br /><applet load="1q22" size="350" color="white" frame="true" align="right" spinBox="true"  

The gene for human hydroxysteroid sulfotransferase (SULT2B1) encodes two peptides, SULT2B1a and SULT2B1b, that differ only at their amino termini. SULT2B1b has a predilection for cholesterol but is also capable of sulfonating pregnenolone, whereas SULT2B1a preferentially sulfonates pregnenolone and only minimally sulfonates cholesterol. We have determined the crystal structure of SULT2B1a and SULT2B1b bound to the substrate donor product 3'-phosphoadenosine 5'-phosphate at 2.9 and 2.4 A, respectively, as well as SULT2B1b in the presence of the acceptor substrate pregnenolone at 2.3 A. These structures reveal a different catalytic binding orientation for the substrate from a previously determined structure of hydroxysteroid sulfotransferase (SULT2A1) binding dehydroepiandrosterone. In addition, the amino-terminal helix comprising residues Asp19 to Lys26, which determines the specificity difference between the SULT2B1 isoforms, becomes ordered upon pregnenolone binding, covering the substrate binding pocket.

1Q22 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=A3P:'>A3P</scene> and <scene name='pdbligand=AND:'>AND</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Q22 OCA].  

[[Category: Lee, K A.]]

[[Category: Lee, Y C.]]

[[Category: Pedersen, L C.]]

[[Category: Strott, C A.]]

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