Har Gobind Khorana

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Hargobind Khorana (born January 9, 1922) is a molecular biologist.

Khorana was born in Raipur (at that time British India, now Pakistan). He was homeschooled by his father, and then he went to D.A.V. Multan High School later in his life. In 1945, he began studies at the University of Liverpool. After earning a Ph. D., he spend a postdoc year in Zürich (1948-49). He then returned to England and worked at the University of Cambridge until 1952. He married Esther Elizabeth Sibler the same year. After that, he worked at universities in Vancouver and Wisconsin.

Khorana was awarded the 1968 Nobel Prize in Medicine (together with Robert W. Holley and Marshall Warren Nirenberg) for describing the genetic code and how it operates in protein synthesis.

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Khorana's synthetic RNA approach

Ribonucleic acid (RNA) with two repeating units (UCUCUCU → UCU CUC UCU) produced two alternating amino acids. This, combined with the Nirenberg and Leder experiment, showed that UCU codes for Serine and CUC codes for Leucine.

RNAs with three repeating units (UACUACUA → UAC UAC UAC, or ACU ACU ACU, or CUA CUA CUA) produced three different strings of amino acids.

RNAs with four repeating units including UAG, UAA, or UGA, produced only dipeptides and tripeptides thus revealing that UAG, UAA and UGA are stop codons.

With this, Dr. Khorana and his team had established that the mother of all codes, the biological language common to all living organisms, is spelled out in three-letter words: each set of three nucleotides codes for a specific amino acid. Their Nobel lecture was delivered on December 12, 1968. Dr. Khorana was also the first to synthesize oligonucleotides, that is, strings of nucleotides. These custom designed pieces of artificial genes are widely used in biology labs for sequencing, cloning and engineering new plants and animals. This invention of Dr. Khorana has become automated and commercialized so that anyone now can order a synthetic gene from any of a number of companies-- one merely needs to fax the genetic sequence to one of the companies to receive an oligonucliotide with the desired sequence.

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