Binding Affinity and Function of the Extremely Disordered Protein Complex Containing Human Linker Histone H1.0 and Its Chaperone ProTα.
Biochemistry
; 57(48): 6645-6648, 2018 12 04.
Article
em En
| MEDLINE
| ID: mdl-30430826
ABSTRACT
It was recently reported that human linker histone H1.0 and its chaperone prothymosin-α (ProTα) form an extremely disordered 11 complex with an ultrahigh affinity (equilibrium dissociation constant KD of â¼2 × 10-12 M) measured using a single-molecule Förster resonance energy transfer method. It was hypothesized that the ultrahigh affinity and extreme disorder may be required for the chaperone function of ProTα, in which it displaces the linker histone from condensed chromatin. Here, we measure the binding affinity for the ProTα-H1.0 complex using isothermal titration calorimetry and report a KD value of (4.6 ± 0.5) × 10-7 M. In addition, we show that ProTα facilitates the formation of the H1.0-nucleosome complex in vitro. The results of our study contrast with those of the previous report and provide new insights into the chaperone function of ProTα. Possible causes for the observed discrepancy in binding affinity are discussed.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Precursores de Proteínas
/
Timosina
/
Histonas
Limite:
Humans
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos