00380nam a2200121Ia 4500008004100000022001400041040001100055100002700066245008400093260005500177300001700232300000900249251112s9999||||xx |||||||||||||| ||und||  a0027-8424  aCNCLSA  aNicholas R. Cozzarelli 0aProceedings of the National Academy Of Sciences of the United States of America  c1999bThe National Academy of SciencesaWashington  aP. 5337-6574  bV.10