8CRA image
Entry Detail
PDB ID:
8CRA
Keywords:
Title:
Structure of the keratin-like domain of SEPALLATA3 and AGAMOUS from Arabidopsis thaliana
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2023-03-08
Release Date:
2024-03-27
Method Details:
Experimental Method:
Resolution:
2.40 Å
R-Value Free:
0.27
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
C 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Floral homeotic protein AGAMOUS
Chain IDs:A, B, C, D
Chain Length:96
Number of Molecules:4
Biological Source:Arabidopsis thaliana
Polymer Type:polypeptide(L)
Description:Developmental protein SEPALLATA 3
Chain IDs:E, F, G, H
Chain Length:98
Number of Molecules:4
Biological Source:Arabidopsis thaliana
Primary Citation
SEPALLATA-driven MADS transcription factor tetramerization is required for inner whorl floral organ development.
Plant Cell 36 3435 3450 (2024)
PMID: 38771250 DOI: 10.1093/plcell/koae151

Abstact

MADS transcription factors are master regulators of plant reproduction and flower development. The SEPALLATA (SEP) subfamily of MADS transcription factors is required for the development of floral organs and plays roles in inflorescence architecture and development of the floral meristem. SEPALLATAs act as organizers of MADS complexes, forming both heterodimers and heterotetramers in vitro. To date, the MADS complexes characterized in angiosperm floral organ development contain at least 1 SEPALLATA protein. Whether DNA binding by SEPALLATA-containing dimeric MADS complexes is sufficient for launching floral organ identity programs, however, is not clear as only defects in floral meristem determinacy were observed in tetramerization-impaired SEPALLATA mutant proteins. Here, we used a combination of genome-wide-binding studies, high-resolution structural studies of the SEP3/AGAMOUS (AG) tetramerization domain, structure-based mutagenesis and complementation experiments in Arabidopsis (Arabidopsis thaliana) sep1 sep2 sep3 and sep1 sep2 sep3 ag-4 plants transformed with versions of SEP3 encoding tetramerization mutants. We demonstrate that while SEP3 heterodimers can bind DNA both in vitro and in vivo and recognize the majority of SEP3 wild-type-binding sites genome-wide, tetramerization is required not only for floral meristem determinacy but also for floral organ identity in the second, third, and fourth whorls.

Legend

Protein

Chemical

Disease

Primary Citation of related structures