Structural basis for the DNA-binding activity of human ARID4B Tudor domain

Autor: Weibin Gong, W. D. Hu, Yingang Feng, Sarah Perrett, Hongwei Yao, Jie Ren
Jazyk: angličtina
Rok vydání: 2021
Předmět:
0301 basic medicine
Tudor domain
HTD
hybrid Tudor domain

Protein Conformation
nuclear magnetic resonance (NMR)
EMSA
electrophoretic mobility shift assay

Sequence Homology
DNA-binding protein
Biochemistry
RMSD
root mean square deviation

03 medical and health sciences
chemistry.chemical_compound
Protein structure
DSC
differential scanning calorimetry

Antigens
Neoplasm

Humans
Protein–DNA interaction
Amino Acid Sequence
tumor suppressor gene
protein structure
Structural motif
protein motif
NMR
nuclear magnetic resonance

Molecular Biology
030102 biochemistry & molecular biology
ITC
isothermal titration calorimetry

RB
retinoblastoma protein

DNA
Cell Biology
HSQC
heteronuclear single quantum coherence

Protein superfamily
CSP
chemical shift perturbation

Neoplasm Proteins
DNA-Binding Proteins
030104 developmental biology
chemistry
protein stability
RBBP1
retinoblastoma-binding protein 1

Biophysics
protein–DNA interaction
AR
androgen receptor

Heteronuclear single quantum coherence spectroscopy
Protein Binding
Retinoblastoma-Binding Protein 1
Research Article
Zdroj: The Journal of Biological Chemistry
ISSN: 1083-351X
0021-9258
Popis: Human ARID4A and ARID4B are homologous proteins that are important in controlling gene expression and epigenetic regulation but have distinct functions. Previous studies have shown that the N-terminal domain of ARID4A is an unusual interdigitated double Tudor domain with DNA-binding activity. However, how the Tudor domain of ARID4B differs from that of ARID4A remains unknown. Here, we found that the ARID4B Tudor domain has significantly weaker DNA affinity than the ARID4A Tudor domain despite sharing more than 80% sequence identity. Structure determination and DNA titration analysis indicated that the ARID4B Tudor domain is also an interdigitated double Tudor domain with a DNA-binding surface similar to ARID4A. We identified a residue close to the DNA-binding site of the Tudor domain that differs between ARID4A and ARID4B. The Leu50 in ARID4A is Glu50 in ARID4B, and the latter forms salt bridges with two lysine residues at the DNA-binding surface. This causes a decrease in the strength of positive charge, thus reducing DNA-binding affinity while significantly increasing protein stability. We also found that a C-terminal extension region enhances the DNA-binding affinity of the ARID4B Tudor domain. This C-terminal extension is disordered and contains a positively charged RGR motif, providing an additional DNA-binding site. Finally, sequence and phylogenetic analyses indicated that the residue differences and the presence of the RGR extension region are conserved. These results provide new insight into the functional differences between ARID4A and ARID4B proteins, as well as elucidating the function of the disordered regions in these proteins.
Databáze: OpenAIRE