Pfab, Alexander and Gronlund, Jesper T. and Holzinger, Philipp and Langst, Gernot and Grasser, Klaus D. (2018) The Arabidopsis Histone Chaperone FACT: Role of the HMG-Box Domain of SSRP1. JOURNAL OF MOLECULAR BIOLOGY, 430 (17). pp. 2747-2759. ISSN 0022-2836, 1089-8638
Full text not available from this repository. (Request a copy)Abstract
Histone chaperones play critical roles in regulated structural transitions of chromatin in eukaryotic cells that involve nucleosome disassembly and reassembly. The histone chaperone FACT is a heterodimeric complex consisting in plants and metazoa of SSRP1/SPT16 and is involved in dynamic nucleosome reorganization during various DNA-dependent processes including transcription, replication and repair. The C-terminal HMG box domain of the SSRP1 subunit mediates interactions with DNA and nucleosomes in vitro, but its relevance in vivo is unclear. Here, we demonstrate that Arabidopsis ssrp1-2 mutant plants express a C-terminally truncated SSRP1 protein. Although the structure of the truncated HMG-box domain is distinctly disturbed, it still exhibits residual DNA-binding activity, but has lost DNA-bending activity. Since ssrp1-2 plants are phenotypically affected but viable, the HMG-box domain may be functionally non-essential. To examine this possibility, SSRP1 A, HMG completely lacking the HMG-box domain was studied. SSRP1 Delta HMG in vitro did not bind to DNA and its interactions with nucleosomes were severely reduced. Nevertheless, the protein showed a nuclear mobility and protein interactions similar to SSRP1. Interestingly, expression of SSRP1 Delta HMG is almost as efficient as that of full-length SSRP1 in supporting normal growth and development of the otherwise nonviable Arabidopsis ssrp1-1 mutant. SSRP1 Delta HMG is structurally similar to the fungal ortholog termed Pob3 that shares clear similarity with SSRP1, but it lacks the C-terminal HMG-box. Therefore, our findings indicate that the HMG-box domain conserved among SSRP1 proteins is not critical in Arabidopsis, and thus, the functionality of SSRP1/SPT16 in plants/metazoa and Pob3/Spt16 in fungi is perhaps more similar than anticipated. (C) 2018 Elsevier Ltd. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | MOBILITY-GROUP BOX; DNA-BINDING PROTEINS; RNA-POLYMERASE-II; SACCHAROMYCES-CEREVISIAE; TRANSCRIPT ELONGATION; NUCLEOSOME REORGANIZATION; CK2 PHOSPHORYLATES; CHROMATIN; POB3; FORM; chromatin; histone; HMG-box domain; DNA/nucleosome interaction; transcript elongation |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften > Lehrstuhl für Zellbiologie und Pflanzenphysiologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 10 Jan 2020 09:57 |
| Last Modified: | 10 Jan 2020 09:57 |
| URI: | https://pred.uni-regensburg.de/id/eprint/14042 |
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