One research group, led by Joseph A. Krzycki, an associate professor of microbiology, had been working for several years with a particular strain of microbe, Methanosarcina barkeri. This organism, a member of the recently identified domain Archaea, is able to convert monomethylamine, dimethylamine and trimethylamine into this greenhouse gas.
Krzycki's research group had isolated specific proteins related to the process in 1995 and, two years later, they had isolated and sequenced one of the genes responsible. Then in 1998, they published a paper showing that the gene had a component called an in-frame amber codon that behaved unusually.
Codons are three-letter "words" identifying the bases DNA uses to specify particular amino acids as building blocks of proteins. Normally, codons signal the start of a protein, its end or a particular amino acid used to construct it. Surprisingly, the codon Krzycki's team identified should have signaled a stop to protein building but it did not.
"Joe and his colleagues found this happening in genes important for all three of the methylamine compounds - something that wasn't supposed to happen," explained Michael Chan, an associate professor of biochemistry and chemistry at Ohio State. Chan led the second research team that identified and determined the structure of the amino acid.
The realization of the codon's odd behavior suggested the
possibility of
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Contact: Joseph A. Krzycki
Krzycki.1@osu.edu
614-292-1578
Ohio State University
23-May-2002