How to create EXTJS model for this xml format

How to create EXTJS model for this xml format

This is the xml format that I will get when I got the return from ajax call.
<root>
<tag1>
<item>
<name>....</name>
<des>......</des>
</item>
<item>
<name>....</name>
<des>......</des>
</item>
<item>
<name>....</name>
<des>......</des>
</item>
</tag1>
<tag2>
<key>.....</key>
<spec>....</spec>
</tag2>
</root>
I will use the item inside tag 1 for a grid table. The information in tag2
will be using for display in a panel.
I know that it is possible to make 2 ajax call query to 2 different store
for 2 different purpose.
But to minimize the ajax call, which mean I only need to do 1 ajax call.
Is that possible to define an extjs model that store such this xml format?
If yes, can you make an example of it?
Thank you.