An Overview of Nucleic Acid Chemistry, Structure, and Function

Abstract

Chemists and early biochemists determined the essential building blocks of living cells and characterized their chemical nature. Among these building blocks were nucleic acids, long-chain polymers composed of nucleotides. Nucleic acids were named based partly on their chemical properties and partly on the observation that they represent a major constituent of the cell nucleus. That nucleic acids form the chemical basis for the transmission of genetic traits was not realized until about 60 years ago (1,2). Prior to that time, there was considerable disagreement among scientists as to whether genetic information was contained in and transmitted by proteins or nucleic acids. It was recognized that chromosomes contained deoxyribonucleic acid as a primary constituent, but it was not known if this DNA carried genetic information or merely served as a scaffold for some undiscovered class of proteins that carried genetic information. However, the demonstration that genetic traits could be transmitted through DNA formed the basis for numerous investigations focused on elucidation of the nature of the genetic code. During the last half-century, numerous investigators have participated in the scientific revolution leading to modern molecular biology. Of particular significance were the elucidation of the structure of DNA (3 –9), determination of structure —function relationships between DNA and RNA (10,11), and acquisition of basic insights into the processes of DNA replication, RNA transcription, and protein synthesis (12 –19). Molecular pathology represents the application of the principles of basic molecular biology to the investigation of human disease processes. Our ever broadening insights into the molecular basis of disease processes continues to provide an opportunity for the clinical laboratory to develop and implement new and novel approaches for diagnosis and prognostic assessment of human disease.