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Dear all<br>
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<div style=""><font size="3">i have protein soaked in Dimethyltindibromide<br><br>in the active site 2 cysteine and 1 aspartic acid<br><br>by help of anomalous map i can see 2 Sn atoms in each subunit in AU<br><br>there is difference in both subunits, Sub-A shows acetate near Sn<br>and Sub-B show phosphate ion, even the position of one of the 2 cystein is different from unit to other
</font><div style=""><font size="3"><font size="3">1-is it normal to see such difference between 2 subunit? <br><br></font><br>also the distances between Sn and surrounding atoms does not suggest covalent binding<br><br>2-the important question is how to confirm if the 2 methyl groups or even one methyl group of dimethlytin are still there or cleaved<br><br>i mean one can not differentiate between density of water and methygroup.<br>How to define coordinate number of Heavy atom and identity of the attached atoms<br>as you will see in the link below (with water) and (with Methyl) the map are the same and as well r-factors<br><br>3-<var id="yiv1615271010yui-ie-cursor"></var>what can i do to confirm presence or cleavage of methyl: collect more data or using other technique like exafs, Mossbauer spectroscopy could help<br><br>(with water)<br><br><a rel="nofollow" target="_blank"
href="http://dl.dropbox.com/u/12001878/Subunit-A.png">http://dl.dropbox.com/u/12001878/Subunit-A.png</a><br> <br><a rel="nofollow" target="_blank" href="http://dl.dropbox.com/u/12001878/subunit-A-anomalous.png">http://dl.dropbox.com/u/12001878/subunit-A-anomalous.png</a></font></div></div>
<div><font size="3"> <br><a rel="nofollow" target="_blank" href="http://dl.dropbox.com/u/12001878/Subunit-B.png">http://dl.dropbox.com/u/12001878/Subunit-B.png</a></font></div>
<div><font size="3"></font> </div>
<div><font size="3"><a rel="nofollow" target="_blank" href="http://dl.dropbox.com/u/12001878/subunit-B-anomalous.png">http://dl.dropbox.com/u/12001878/subunit-B-anomalous.png</a></font></div>
<div><font size="3"></font> </div>
<div><font size="3">(with methyl)<br></font></div>
<div><font size="3"></font> </div>
<div><font size="3"><a rel="nofollow" target="_blank" href="http://dl.dropbox.com/u/12001878/DimethylTin-subunit-A-alt-conf.png">http://dl.dropbox.com/u/12001878/DimethylTin-subunit-A-alt-conf.png</a></font></div>
<div><font size="3"> <br><a rel="nofollow" target="_blank" href="http://dl.dropbox.com/u/12001878/DimethylTin-subunit-B.png">http://dl.dropbox.com/u/12001878/DimethylTin-subunit-B.png</a><br><br>N.B: resolution 1.7 A<br>r factors and molprop are perfect.<br><br><br>thank you for your time<br><br>haytham<br>biochimi<br>canada</font></div></div></div><br><br></div></div></div></div><br><br></div></div></div></div><br><br></div></div></div></div><br><br></div></div></div></body></html>