Комп’ютерне моделювання просторової структури білка-модулятора гіберелінової відповіді RHT-1 Triticum aestivum L. з родини DELLA-GRAS білків

Анотація

Aim. Modeling of 3D structure of wheat RHT-1 protein (Reduced height protein 1, Ta-RHT1) which is a modulator of plant growth hormone gibberellin response and belongs to the DELLA subfamily of GRAS family of plant protein repressors of transcription. Methods. BLAST-analysis, 3D structure modeling by Robetta, I-TASSER and Swiss-Model web‑servers. Results. For Ta-RHT1 protein the secondary and subdomain structure and regions of high structural disorder are predicted. Crystal structures of SAM-dependent methyltransferases containing β-layer with seven β-strands were used as structural templates for modeling. Conservative tyrosine Y594 residue in SAW-domain can probably be phosphorylated and ensure the regulation of activity of Ta-RHT1 protein. N-terminal deletion M1-E64 in Ta-RHT1 is associated with altered response to growth hormone gibberellin and therefore shorter stalk of wheat and its resistance to lodging, leads to loss of specific ³⁸DELLA⁴² and ⁶⁰LExLE⁶⁴ motifs. Since ³⁸DELLA⁴² motif is required for binding to gibberellin receptor, apparently these mutations resulted in violations of specific binding of Ta-RHT1 with GID1 and violation of the subsequent proteolysis and ubiquitination of DELLA-protein.

Keywords: DELLA protein, GRAS family, gibberellin response, structure modeling.