?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Warren%2C+David&rft.aulast=Warren&rft.aufirst=David&rft.issue=14&rft.volume=100&rft.date=8+July+2003&rft.issn=0027-8424&rft.atitle=Identification+of+the+lambda+integrase+surface+that+interacts+with+Xis+reveals+a+residue+that+is+also+critical+for+Int+dimer+formation.&rft.title=Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America&rft.pages=8176-81&rft.genre=article