What is the expression vector, pSG5?

[slee at opal.tufts.edu]

  Help! Help!  I need to know what is the mammalian expression vector, pSG5.
Pierre Chambon uses this vector to express alot of his receptors in transient
transfection assays.  Anyone know where I can get a map?  What is the promoter
driving this vector?  Can this vector also be used for in vitro transcription/
translation?  What is the polylikner for this vector?  I need to know this
information pretty fast.  Please e-mail me at:  slee at opal.tufts.edu or FAX the
info to me at (617) 636-4719.  I REALLY appreciate the help.  Steph