Har Gobind Khorana

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

Khorana's synthetic RNA approach

RNAs 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 Ser and CUC for Leu.

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

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

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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. Dr. Khorana's invention of the synthesis of oligonucleotides has become an indispensable tool in biotechnology. 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.

Related Topics:
Codes - Nucleotides - Amino acid - Nobel - Oligonucleotide - Genetic sequence

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