One Gene One Enzyme Hypothesis

One gene one enzyme is a hypothesis in which the production of protein is encoded by gene in a metabolic pathway. Enzymes are produced from single or group of protein. Hence the control of gene expression result in control of protein expression ultimately results in control of enzyme expression. Gregor Beadle and Edward Tatum was the first to introduce one gene one enzyme hypothesis in the year 1941. They experimented genetic mutation effects first in Neurospora crassa, a mold in the year 1945.

Hypothesis

Moweus experimented first one gene one enzyme idea in the year 1930 with Chalmydomonas. According to his results,different genes are responsible for the production of different enzymes by different mechanism resulting in the formation of different hormones. However his experiments are found to be non replicate and are challenged by Beadle and Tatum.

Beadle and Tatum published their work in National Academy of Science Proceedings in the year 1941. Gene can control and express according to the specific requirement sounds to be good. Gene being a part of the human system can control the production of enzyme and or enzyme specificity is amazing fact. Laboratory experiment was carried out with mold Neurospora crassa along with other model organisms like E. Coli. Neurospora crassa is a bread mold. As per Thomas Hunt Morgan research Neurospora crassa is subjected easily to genetic mutations. It grows easily in simple medium and at a faster rate. Production of ascospores by Neurospora crassa can be easily isolated for genetic mutant analysis. When exposed to X-ray diffraction they produced mutations. Nutritional mutants have some beneficial applications as nutrition during Second World War. The experimental result prove each and every step of metabolism is controlled enzyme and in turn by a single gene. Beadle found that specificity of gene can control the gene expression. According to Avery, Macleod and McCarty experiments, it is evident that gene contains many number of proteins or nucleoproteins. This one gene and one protein enzyme gave outline for protein theory of gene. Norman Horowitz baptized it as one gene one enzyme hypothesis. It is widely accepted by all individuals and is not challenged.