logging in or signing up Newly discovered amino acids n0prof Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 329 Category: Science & Tech.. License: All Rights Reserved Like it (0) Dislike it (0) Added: December 20, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Newly discovered amino acids : Newly discovered amino acids Under supervision of \ Dr. Tayseer By\Mohamed Tag elDine Firstly the known amino acids : Firstly the known amino acids Selenocysteine: The 21st Amino Acid : Selenocysteine: The 21st Amino Acid SeC itself is highly toxic to cells in high doses Necessary for selenoproteins particularly An operon consisting of four genes known as the sel operon is necessary for the incorporation of selenocysteine into proteins. Slide 4: In fact Selenocysteine is encoded by the UGA codon, the umber codon, which is normally a termination codon. But there are only 64 possibilities for a triplet code, and each has been assigned an amino acid already so how can Selenocysteine be encoded? How this happens ?! : How this happens ?! In Prokaryotes Sel operon is the responsible for this process by its four genes:- Sel A converts serine to dehydeoalanine Sel B translated for the EF-Tu like factor Sel C codes for the specific selenocysteine tRNA sel D - “activates” HSe- Pyrrolysine: The 22nd Amino acid : Pyrrolysine: The 22nd Amino acid After the discovery of the selenocysteine and its unusual mechanism of incorporation to the protein That left open the question of whether future amino acids would follow the traditional path of the first 20 amino acids or the unusual route taken by 21st In the end, traditional won out. : In the end, traditional won out. But, how did they discover it ??? : But, how did they discover it ??? In the study of a common class of compounds - the methylamines - that transformed into methane by methanogens bacteria. Krzycki's research group had isolated specific proteins related to the process in 1995 and, two years later, they had isolated and sequenced one of the genes responsible Slide 10: While sequencing the gene it was unexpected to see the umber codon (UGA) inside the gene Firstly it thought to be a normal lysine, But after crystallization and using the X-ray it was identified as a new amino acid (pyrrolysine) Thanks a lot : Thanks a lot You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Newly discovered amino acids n0prof Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 329 Category: Science & Tech.. License: All Rights Reserved Like it (0) Dislike it (0) Added: December 20, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Newly discovered amino acids : Newly discovered amino acids Under supervision of \ Dr. Tayseer By\Mohamed Tag elDine Firstly the known amino acids : Firstly the known amino acids Selenocysteine: The 21st Amino Acid : Selenocysteine: The 21st Amino Acid SeC itself is highly toxic to cells in high doses Necessary for selenoproteins particularly An operon consisting of four genes known as the sel operon is necessary for the incorporation of selenocysteine into proteins. Slide 4: In fact Selenocysteine is encoded by the UGA codon, the umber codon, which is normally a termination codon. But there are only 64 possibilities for a triplet code, and each has been assigned an amino acid already so how can Selenocysteine be encoded? How this happens ?! : How this happens ?! In Prokaryotes Sel operon is the responsible for this process by its four genes:- Sel A converts serine to dehydeoalanine Sel B translated for the EF-Tu like factor Sel C codes for the specific selenocysteine tRNA sel D - “activates” HSe- Pyrrolysine: The 22nd Amino acid : Pyrrolysine: The 22nd Amino acid After the discovery of the selenocysteine and its unusual mechanism of incorporation to the protein That left open the question of whether future amino acids would follow the traditional path of the first 20 amino acids or the unusual route taken by 21st In the end, traditional won out. : In the end, traditional won out. But, how did they discover it ??? : But, how did they discover it ??? In the study of a common class of compounds - the methylamines - that transformed into methane by methanogens bacteria. Krzycki's research group had isolated specific proteins related to the process in 1995 and, two years later, they had isolated and sequenced one of the genes responsible Slide 10: While sequencing the gene it was unexpected to see the umber codon (UGA) inside the gene Firstly it thought to be a normal lysine, But after crystallization and using the X-ray it was identified as a new amino acid (pyrrolysine) Thanks a lot : Thanks a lot