The Molecular Basis Of Inheritance

Gene was artificialy synthesized first by H.G. Khorana.

The existence of tRNA was first hypothesised by Francis Crick, based on the assumption that there must exist an adapter molecule capable of mediating the translation of the RNA alphabet into the protein alphabet. In 1965, a publication by Robert W Holley reported the primary structure and suggested three secondary structures. The clover leaf structure was ascertained by several other studies in the following years and was finally confirmed using X-ray crystallography studies in 1974. Two independent groups, Kim Sung Hou working under Alexander Rich and a British group headed by Aaron Klug, published the same crystallography findings within a year.

Histones are a set of positively-charged, basic proteins. Histones are rich in the basic amino acid residues lysines and arginines. Both the amino acid residues carry positive charges in their side chains. Two molecules of each of the four types of histones- and are organized to form histone octamers. These form the inner core of nucleosome. The negatively charged DNA is wrapped around the positively-charged histone octamer to form a structure called nucleosome.

Mathew Messelson and Franklin Stahl gave/prooved semi-conservative mode of DNA replication for the fist time in bacterium E coy/with help of heavy isotope of nitrogen as postulated previously by Watson and Crick. Kornberg and Ochoa carried out the first in vitro synthesis of DNA with template and RNA respectively.