Application of DNA Sequence and Clone Data

Overview

The sequence of nucleotides within a DNA molecule can yield a wealth of information. Important biological features such as amino acid sequence, exact amino acid composition, and gene structure are contained within sequences. The data can be used for highly specific manipulations of cloned DNA, such as changing a single nucleotide, substituting promoters between genes, and fusing of genes to yield hybrid (heterologous) proteins. Probes can also be designed for a variety of uses, including the detection of genetic diseases and pathogenic microbes.

The nucleotide sequence of a clone is fundamental. From this data, all known restriction sites, subsequences, and coding regions can be determined. The comparison of sequences allows for the elucidation of important biological motifs, such as the Pribnow box, the alteration of sequences through site-directed mutagenesis, and gene fusion methodologies. The synthesis of homologous oligonucleotides allows for the design of highly specific probes (or primers). These oligonucleotides, or primers, have led to the development of an extremely powerful technique, the polymerase chain reaction (PCR). Based on the specificity of primers, PCR allows for the in vitro replication of small regions of DNA.

The objective of the preceding twelve chapters was to gather data from a protein and clone its associated gene. Whether you were successful in this endeavor or simply followed the process, that objective has been achieved. In reality, the means by which you cloned the MEL1 gene, however, is not important. It is the gene itself, including its nucleotide sequence, that is important.

Now that you have a gene and its sequence, what do you do with it? This chapter will focus on the analysis of DNA sequence data and on one method for its application.