[BioC] XML data

[S Peri]

Hi Group,
  I want to create a database of Affy probe sequences
that can be used to BLAST (NCBI local BLAST) my
sequence files against this database.  For this,  I
downloaded the XML based  hgu133a (1.5.0)Human 
gzipped XML data from BioConductor.  The file
extension is weird which is hgu133plus2.xml.gz.xml,
this is not in gzipped format. When I try to open I
can see XML tags and I do not see any sequence data.
This looks like annotation data.  
 
 
Could any one please suggest which is the correct file
that has the sequence data for all affy chips.  Also,
is there some way to format that sequence data for
NCBI BLASTable database.  

Thank you. 

Cheers
SP