Biochemistry
6th Edition
ISBN: 9781305577206
Author: Reginald H. Garrett, Charles M. Grisham
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 26, Problem 6P
Allosteric Regulation of Ribonucleotide Reductase by ATP and Deoxynucleotides Describe the underlying rationale for the regulatory effects exerted on ribonucleotide reductase by ATP, dATP, dTTP, and dGTP.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A Leu →Ala mutation at a site buried in the core of the enzyme lysozymeis found to be destabilizing. Explain the observed effect of this mutationon lysozyme stability by predicting how enthalpy (ΔH°), conformationalentropy (ΔS°peptide), and the hydrophobic effect (ΔS°solvent) are expected to change for the mutant compared to wild-type lysozyme. Explain how ΔG°for unfolding is affected by your predicted changes in enthalpy or entropy.
Describe the two sequential reactions that occur in the activesite of aminoacyl-tRNA synthetases.
What is the smallest number of molecules of ATP and GTP consumed in the synthesis of a 200- residue protein, starting from amino acids? Assume that the hydrolysis of PP i is equivalent to the hydrolysis of ATP for this calculation.
Chapter 26 Solutions
Biochemistry
Ch. 26 - Prob. 1PCh. 26 - Prob. 2PCh. 26 - Allosteric Regulation of Purine and Pyrimidine...Ch. 26 - Inhibition of Purine and Pyrimidine Metabolism by...Ch. 26 - Prob. 5PCh. 26 - Allosteric Regulation of Ribonucleotide Reductase...Ch. 26 - Prob. 7PCh. 26 - Prob. 8PCh. 26 - Prob. 9PCh. 26 - Prob. 10P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biochemistry and related others by exploring similar questions and additional content below.Similar questions
- You have isolated a new protease that cleaves peptide bonds on the carboxyl side of Asp and Glu. Based on the enzyme's inactivation by DIPF, you suspect that it may utilize a mechanism similar to chymotrypsin. The difference in specificity might be explained by the absence of the S1 binding pocket. replacement of serine 195 with a positively charged residue. presence of a positively charged residue in the S1 binding pocket. presence of a negatively charged residue in the S1 binding pocket.arrow_forwardCan you please order the following steps involving the regeneration of ribonucleotide reductase that occurs in most animals so that it may carry out the formation of deoxyribonucleotides. (Note that not all steps are shown.) 1. Reduction of thioredoxin 2. Reduction of ribonucleotide reductase 3. Oxidation of thioredoxin reductase 4. Reduction of thioredoxin reductasearrow_forwardRefer to the reaction scheme of the GAPDH catalyzed formation of 1,3-BPG. In the reaction, the nucleophile in step (4) is an inorganic phosphate molecule. The enzyme active site is elaborately constructed so that inorganic phosphate, not water, acts as the nucleophile. What advantage is gained by using inorganic phosphate, instead of water, as the nucleophile? Discuss in terms of the energy yield of glycolysis. No need to calculate the total net energy yield of glycolysis.arrow_forward
- Lysozyme is an enzyme that hydrolyzes bacterial cell wall polysaccharides. When this reaction is carried out in the presence of H218O, it is observed that there is retention of configuration at the C1 carbon of the D site sugar as shown below: Would this result suggest that the enzyme mechanism involves the direct nucleophilic attack of water at C1 or that the enzyme mechanism involves attack by a nucleophilic amino acid side chain of the enzyme that generates a transient covalent intermediate?arrow_forwardAmino transferases catalyze the transfer of amino groups to alpha-keto acids with pyridoxal phosphate as the prosthetic group. Pyridoxal phosphate can accept an amino group, and its aminated form, pyridoxamine phosphate, can donate its amino group to an alpha-keto acid. Illustrate the detailed mechanism of the transamination reaction in the active site of an aminotransferase. Use the glutamate oxaloacetate transaminase as an example.arrow_forwardDescribe the mechanism of action of 1 cycle of the ubiquitin (Ub) ligase system. Describe how the E1, E2 and E3 ligases work to covalently link Ub to the target protein, including which uses an energy source (and how), and the operative amino acids on the enzymes, Ub and target proteinarrow_forward
- After being stabilized with supplemental oxygen, a blood transfusion, and medication to help with the pain, JJ was prescribed the drug hydroxyurea to help increase the level of fetal hemoglobin (ay2) in the red blood cell. Though the exact pharmacological effect of hydroxyurea is unclear in the treatment of Sickle Cell Disease, it is known that the drug is an inhibitor of ribonucleotide reductase and acts to transiently inhibit deoxyribonucleotide synthesis in dividing cells. Q5: In which phase of the cell cycle does hydroxyurea produce its main effect?arrow_forwardThe allosteric properties of aspartate transcarbamoylase have been discussed in detail in this chapter. What is the function of aspartate transcarbamoylase?arrow_forwardMany blood clotting proteins undergo a post-translational modification in which specific glutamic acid residues (Glu) in the protein are converted to gamma-carboxyglutamic acid residues (Gla). See reaction scheme below. An example is the blood clotting protein Factor IX, which has 12 Glu in its N-terminus converted to Gla. This modification gives Factor IX the ability to bind calcium and phospholipid membranes. Bacteria do not have the enzyme required to convert Glu to Gla and therefore Factor IX proteins expressed in bacteria would not have the proper modifications. How might you engineer the translational apparatus of a bacterial cell line so that it produces Factor IX with Gla in the appropriate positions. How would you ensure that only the 12 Glu in Factor IX that are normally converted to Gla and not just all Glu (Limit 5-6 senetnces)?arrow_forward
- When hyaluronan synthase from Pasteurella multocida was expressed in E. coli, the bacteria spun out a capsule of hyaluronan. This reaction was analyzed using purified membrane fragments containing the hyaluronan synthase, a radio-labeled tetrasaccharide acceptor (Part A), along with the activated forms of the sugar subunits: UDP-N-acetylglucosamine and UDP-glucuronic acid. In short incubations with the complete mixture, the tetrasaccharide primer elongated by several units, although only odd-numbered chains were visible (Part B lane 2). If one or both activated sugars were left out, the results shown in lanes 3-5 (Part B) were obtained. Why do you suppose that only odd-number chains are visible in your assay? (A) ACCEPTOR nonreducing end HO- HO OH COO glucuronic acid (GICUA) HO- CH3 T C=O I NH CH₂ OH N-acetylglucosamine (GlcNAc) COO но- HO OH OH I CH₂ reducing end NH C=O CH3 Choose one: O A. Synthase adds GlcNAc much more slowly than it adds GICUA. O B. One of the monosaccharide…arrow_forwardLike ribonuclease A, lysozyme from T4 phage is a model enzyme for understanding the energetics and pathways of protein folding. Unlike ribonuclease A, T4 lysozyme does not contain any disulfide bonds. A number of studies have quantified the thermodynamic contributions individual amino acid residues and their interactions make to lysozyme folding. An ion pair between an Asp residue and a His residue in lysozyme contributes 13-21 kJ/mol of favorable folding energy at pH 6.0. However, this ion pair contributes much less to lysozyme folding at either pH 2.0 or pH 10.0. Why does the Asp-His ion pair contribute more energy at pH 6.0 than at low or high pH? At pH 10.0, Asp is protonated and His may be deprotonated. At pH 6.0, Asp is protonated and His may be deprotonated. At pH 2.0, Asp and His are both deprotonated. At pH 10.0, Asp and His are both protonated. ● At pH 6.0, Asp is deprotonated and His may be protonated.arrow_forwardKinases are enzymes that transfer a phosphoryl group from a nucleosidetriphosphate. Which of the following are valid kinase-catalyzed reactions? (a) ADP + CMP → AMP + CDP. (b) AMP + ATP → 2 ADP.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...
Biology
ISBN:9781285866932
Author:Lauralee Sherwood
Publisher:Cengage Learning
Macromolecules | Classes and Functions; Author: 2 Minute Classroom;https://www.youtube.com/watch?v=V5hhrDFo8Vk;License: Standard youtube license