Conformational Dynamics of Phytoglobin BvPgb1.2 from Beta vulgaris ssp. vulgaris .
Simon ChristensenOlof StenströmMikael AkkeLeif BülowPublished in: International journal of molecular sciences (2023)
Plant hemoglobins, often referred to as phytoglobins, play important roles in abiotic stress tolerance. Several essential small physiological metabolites can be bound to these heme proteins. In addition, phytoglobins can catalyze a range of different oxidative reactions in vivo. These proteins are often oligomeric, but the degree and relevance of subunit interactions are largely unknown. In this study, we delineate which residues are involved in dimer formation of a sugar beet phytoglobin type 1.2 (BvPgb1.2) using NMR relaxation experiments. E. coli cells harboring a phytoglobin expression vector were cultivated in isotope-labeled ( 2 H, 13 C and 15 N) M9 medium. The triple-labeled protein was purified to homogeneity using two chromatographic steps. Two forms of BvPgb1.2 were examined, the oxy-form and the more stable cyanide-form. Using three-dimensional triple-resonance NMR experiments, sequence-specific assignments for CN-bound BvPgb1.2 were achieved for 137 backbone amide cross-peaks in the 1 H- 15 N TROSY spectrum, which amounts to 83% of the total number of 165 expected cross-peaks. A large proportion of the non-assigned residues are located in α-helixes G and H, which are proposed to be involved in protein dimerization. Such knowledge around dimer formation will be instrumental for developing a better understanding of phytoglobins' roles in planta.
Keyphrases
- magnetic resonance
- high resolution
- binding protein
- induced apoptosis
- amino acid
- protein protein
- pet imaging
- healthcare
- poor prognosis
- single molecule
- solid state
- escherichia coli
- molecular dynamics
- squamous cell carcinoma
- lymph node metastasis
- signaling pathway
- fluorescent probe
- small molecule
- transcription factor
- arabidopsis thaliana