Solved

Passage Interactions Between Positively Charged Histones and Negatively Charged Nucleic Acids

Question 93

Multiple Choice

Passage
Interactions between positively charged histones and negatively charged nucleic acids are altered by acetylation and methylation of histone subunits.  These different post-translational modifications are recognized by histone-binding proteins such as BROMO domain Adjacent to Zinc finger 2B (BAZ2B) .  BAZ2B has a net negative charge but contains a lysine-rich regulatory region between its two histone-binding domains.NMR data revealed potential interactions between BAZ2B and histone subunit H3 (Figure 1) .  Binding was confirmed by isothermal titration calorimetry (ITC) , which measures enthalpy of binding when a protein solution is titrated with ligand injections of equal volume and concentration.  Each injection results in a negative peak as heat is released.  Figure 2 shows ITC results when wild-type BAZ2B (WT) or BAZ2B with the regulatory region removed (10M+) were titrated with unmodified histone 3 (H3) or H3 that was acetylated at lysine-14 (H3K14ac) .  In each case, the Hill coefficient was approximately 1.To test binding in a biological setting (in vivo) , WT and 10M+ BAZ2B were extracted from cell lysates on affinity columns containing H3 or H3K14ac covalently attached to beads.  BAZ2B was then eluted and binding was quantified by Western blot (Figure 3) .
Passage Interactions between positively charged histones and negatively charged nucleic acids are altered by acetylation and methylation of histone subunits.  These different post-translational modifications are recognized by histone-binding proteins such as BROMO domain Adjacent to Zinc finger 2B (BAZ2B) .  BAZ2B has a net negative charge but contains a lysine-rich regulatory region between its two histone-binding domains.NMR data revealed potential interactions between BAZ2B and histone subunit H3 (Figure 1) .  Binding was confirmed by isothermal titration calorimetry (ITC) , which measures enthalpy of binding when a protein solution is titrated with ligand injections of equal volume and concentration.  Each injection results in a negative peak as heat is released.  Figure 2 shows ITC results when wild-type BAZ2B (WT) or BAZ2B with the regulatory region removed (10M+) were titrated with unmodified histone 3 (H3) or H3 that was acetylated at lysine-14 (H3K14ac) .  In each case, the Hill coefficient was approximately 1.To test binding in a biological setting (in vivo) , WT and 10M+ BAZ2B were extracted from cell lysates on affinity columns containing H3 or H3K14ac covalently attached to beads.  BAZ2B was then eluted and binding was quantified by Western blot (Figure 3) . <strong>Figure 1</strong>  Electrostatic interactions between H3 and BAZ2B amino acid residues <strong>Figure 2</strong>  ITC traces (A) and K<sub>d</sub> values (B) of WT BAZ2B and 10M+ BAZ2B titrated with either unmodified H3 or H3Ka4ac <strong>Figure 3</strong>  Western blot of BAZ2B recovered from unmodified or acetylated H3 columns Adapted from Kostrhon S, Kontaxis G, Kaufmann T, et al. A histone-mimicking interdomain linker in a multidomain protein modulates multivalent histone binding. J Biol Chem. 2017;292(43) :17643-17657. -Based on information in the passage, NMR data indicated electrostatic interactions involving all of the following amino acids EXCEPT: A) lysine. B) aspartate. C) arginine. D) glutamate. Figure 1  Electrostatic interactions between H3 and BAZ2B amino acid residues
Passage Interactions between positively charged histones and negatively charged nucleic acids are altered by acetylation and methylation of histone subunits.  These different post-translational modifications are recognized by histone-binding proteins such as BROMO domain Adjacent to Zinc finger 2B (BAZ2B) .  BAZ2B has a net negative charge but contains a lysine-rich regulatory region between its two histone-binding domains.NMR data revealed potential interactions between BAZ2B and histone subunit H3 (Figure 1) .  Binding was confirmed by isothermal titration calorimetry (ITC) , which measures enthalpy of binding when a protein solution is titrated with ligand injections of equal volume and concentration.  Each injection results in a negative peak as heat is released.  Figure 2 shows ITC results when wild-type BAZ2B (WT) or BAZ2B with the regulatory region removed (10M+) were titrated with unmodified histone 3 (H3) or H3 that was acetylated at lysine-14 (H3K14ac) .  In each case, the Hill coefficient was approximately 1.To test binding in a biological setting (in vivo) , WT and 10M+ BAZ2B were extracted from cell lysates on affinity columns containing H3 or H3K14ac covalently attached to beads.  BAZ2B was then eluted and binding was quantified by Western blot (Figure 3) . <strong>Figure 1</strong>  Electrostatic interactions between H3 and BAZ2B amino acid residues <strong>Figure 2</strong>  ITC traces (A) and K<sub>d</sub> values (B) of WT BAZ2B and 10M+ BAZ2B titrated with either unmodified H3 or H3Ka4ac <strong>Figure 3</strong>  Western blot of BAZ2B recovered from unmodified or acetylated H3 columns Adapted from Kostrhon S, Kontaxis G, Kaufmann T, et al. A histone-mimicking interdomain linker in a multidomain protein modulates multivalent histone binding. J Biol Chem. 2017;292(43) :17643-17657. -Based on information in the passage, NMR data indicated electrostatic interactions involving all of the following amino acids EXCEPT: A) lysine. B) aspartate. C) arginine. D) glutamate. Figure 2  ITC traces (A) and Kd values (B) of WT BAZ2B and 10M+ BAZ2B titrated with either unmodified H3 or H3Ka4ac
Passage Interactions between positively charged histones and negatively charged nucleic acids are altered by acetylation and methylation of histone subunits.  These different post-translational modifications are recognized by histone-binding proteins such as BROMO domain Adjacent to Zinc finger 2B (BAZ2B) .  BAZ2B has a net negative charge but contains a lysine-rich regulatory region between its two histone-binding domains.NMR data revealed potential interactions between BAZ2B and histone subunit H3 (Figure 1) .  Binding was confirmed by isothermal titration calorimetry (ITC) , which measures enthalpy of binding when a protein solution is titrated with ligand injections of equal volume and concentration.  Each injection results in a negative peak as heat is released.  Figure 2 shows ITC results when wild-type BAZ2B (WT) or BAZ2B with the regulatory region removed (10M+) were titrated with unmodified histone 3 (H3) or H3 that was acetylated at lysine-14 (H3K14ac) .  In each case, the Hill coefficient was approximately 1.To test binding in a biological setting (in vivo) , WT and 10M+ BAZ2B were extracted from cell lysates on affinity columns containing H3 or H3K14ac covalently attached to beads.  BAZ2B was then eluted and binding was quantified by Western blot (Figure 3) . <strong>Figure 1</strong>  Electrostatic interactions between H3 and BAZ2B amino acid residues <strong>Figure 2</strong>  ITC traces (A) and K<sub>d</sub> values (B) of WT BAZ2B and 10M+ BAZ2B titrated with either unmodified H3 or H3Ka4ac <strong>Figure 3</strong>  Western blot of BAZ2B recovered from unmodified or acetylated H3 columns Adapted from Kostrhon S, Kontaxis G, Kaufmann T, et al. A histone-mimicking interdomain linker in a multidomain protein modulates multivalent histone binding. J Biol Chem. 2017;292(43) :17643-17657. -Based on information in the passage, NMR data indicated electrostatic interactions involving all of the following amino acids EXCEPT: A) lysine. B) aspartate. C) arginine. D) glutamate. Figure 3  Western blot of BAZ2B recovered from unmodified or acetylated H3 columns
Adapted from Kostrhon S, Kontaxis G, Kaufmann T, et al. A histone-mimicking interdomain linker in a multidomain protein modulates multivalent histone binding. J Biol Chem. 2017;292(43) :17643-17657.
-Based on information in the passage, NMR data indicated electrostatic interactions involving all of the following amino acids EXCEPT:


A) lysine.
B) aspartate.
C) arginine.
D) glutamate.

Correct Answer:

verifed

Verified

Unlock this answer now
Get Access to more Verified Answers free of charge

Related Questions

Q88: Passage<br>DNA polymerization is one of the most

Q89: Passage<br>The influenza A virus is an enveloped

Q90: Amino acid catabolism releases nitrogen in the

Q91: Scientists could confirm that an allosteric effector

Q92: Acetylation of lysine residues in histones increases

Q94: Passage<br>The cystic fibrosis transmembrane conductance regulator (CFTR)

Q95: Passage<br>Spinocerebellar ataxia 3 (SCA3) is a neurodegenerative

Q96: Passage<br>Nerve cells must maintain the composition of

Q97: Passage<br>Human gamma-glutamyl transpeptidase (hGGT) is an enzyme

Q98: Passage<br>Antimicrobial peptides are an important component of