Halvorson Professor of Bacteriology and Molecular Biology, Emeritus
1550 Linden Drive
Phone: (608) 262-3054
William H. McClain is Halvorson Professor of Bacteriology and Molecular Biology, Emeritus, at the University of Wisconsin-Madison. His theoretical and bench experiments (1967-present) unravel the mechanisms of complex and essential biological processes and set him apart as a pioneer in the biological sciences.
TRANSFER RNA (tRNA) converts the instructions in a gene into amino acid subunits, forming protein. Proteins are composed of 20 amino acid types, wherein each amino acid type corresponds to one type of tRNA. The tRNA is built of nucleotide subunits. The sequence of nucleotides in a tRNA is highly variable and determines the specificity of each tRNA for its amino acid.
REPRESENTATION of a tRNA, comprised of a repeating backbone (blue line) with one of four pendent nucleotides at 76 sites (yellow circles). McClain's original computational analysis of the nucleotide sequences of the 20 types of tRNA enabled him to predict which nucleotides were both favored by each tRNA acceptor type and disfavored by the other 19 tRNAs. Larger yellow circles were more predictive. Guided by computer analysis, he chemically redesigned a tRNA gene from type #1 to type #2. Protein sequencing revealed that cells containing the redesigned tRNA switched their specificity to that of type #2.