Enzyme Analysis: The Rationale and Use of Enzyme Assays in Assigning Function to Gene Nucleotide Sequences and the Procedures for the Assay of Three E

An issue of some biological currency pertains to the identification of the functional potential of cells as deduced from the nucleotide sequence of their genes. In effect, nucleotide sequences of genes assigned in some confidence to expressed proteins and function in one cell are taken, when found in the genomes of other cells, to be indicators of the presence of the same function. However, such comparisons have never been found to be perfectly identical. The level of dissimilarity often casts some doubt on the identification or functional assignment of genes. The assignment of enzymatic function by comparison of gene nucleotide sequences alone was recognized as questionable and, hence, only putative even by the first workers to sequence a genome completely (1 ,2 ). One of the problems in assigning gene sequences was characterized by these workers as being the result of low similarities between known sequences from other species and those being analyzed. The matches might be so low that they were not detectable as similar.