[1] Univ N Carolina, Lineberger Comprehens Canc Ctr, Dept Biochem & Biophys, Curriculum Genet & Mol Biol, Chapel Hill, NC 27599 USA
[2] Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Biochem, Div Nucle Acids Enzymol,Howard Hughes Med Inst, Piscataway, NJ 08854 USA