00382nam a2200121Ia 4500008004100000022001400041040001100055100002700066245008400093260005500177300001800232300001000250251112s9999||||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. 9967-10944 bV. 96