[1] Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA
[2] Michigan State Univ, Dept Mol Genet, E Lansing, MI 48824 USA
[3] Michigan State Univ, Dept Chem Engn & Mat Sci, E Lansing, MI 48824 USA
[4] Princeton Univ, Dept Chem, Princeton, NJ 08544 USA
[5] UMDNJ New Jersey Med Sch, Dept Microbiol & Mol Genet, Newark, NJ 07103 USA