2-1f_regulation_of_aa_synthesis

2-1f_regulation_of_aa_synthesis - tyrosine inhibits the...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Feedback inhibition schemes for the control of amino acid biosynthesis The activity of amino acid biosynthetic enzymes is often controlled by feedback inhibition. The first irreversible reaction in a pathway is usually the target of regulation. The final product of the pathway is usually the inhibitor. Inhibition schemes include sequential feedback control , enzyme multiplicity , and concerted feedback control.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Classical example of feedback inhibition: regulation of threonine deaminase A B C D E Z threonine α -ketobutyrate isoleucine
Background image of page 2
QuickTimeª and a decompressor are needed to see this picture. Feedback inhibition by tryptophan anthranilate synthase anthranilate phosphoribosyl transferase
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Regulation of branched biosynthetic pathways Sequential Feedback Control D E Y A B C F G Z
Background image of page 4
Example of sequential feedback inhibition: aromatic amino acid biosynthesis in B. subtilis Chorismate inhibits the DAHP synthase
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
QuickTimeª and a decompressor are needed to see this picture.
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: tyrosine inhibits the dehydrogenase and phenylalanine inhibits the dehydratase Inhibition of the prephenate branches in B. subtilis Enzyme multiplicity D E Y A B C F G Z Two different enzymes catalyze the first common step. Example of enzyme multiplicity: aromatic amino acid synthesis in E. coli three different enzymes catalyze this step one is inhibited by tyrosine one is inhibited by phenylalanine one is inhibited by tryptophan QuickTime and a decompressor are needed to see this picture. Example of enzyme multiplicity: aromatic amino acid synthesis in E. coli (continued) two different mutases catalyze this step. one is inhibited by phenylalanine one is inhibited by tyrosine Concerted feedback control D E Y A B C F G Z inhibition by (Y + Z) Inhibition is more than additive. Concerted feedback inhibition is not observed in amino acid biosynthesis!!!...
View Full Document

This note was uploaded on 02/17/2012 for the course CHEM 212 taught by Professor Staff during the Fall '10 term at Rutgers.

Page1 / 10

2-1f_regulation_of_aa_synthesis - tyrosine inhibits the...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online