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