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Crystallographic analysis and phasing of iron-assimilating protein 1 (FEA1) from Chlamydomonas reinhardtii
As an essential component of protein cofactors, iron is important for all photosynthetic organisms. In Chlamydomonas reinhardtii, iron levels are strictly controlled by proteins such as iron-assimilating protein 1 (FEA1). This periplasmic protein is expressed under conditions of iron deficiency, but...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
International Union of Crystallography
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8098128/ https://www.ncbi.nlm.nih.gov/pubmed/33949973 http://dx.doi.org/10.1107/S2053230X21003952 |
Sumario: | As an essential component of protein cofactors, iron is important for all photosynthetic organisms. In Chlamydomonas reinhardtii, iron levels are strictly controlled by proteins such as iron-assimilating protein 1 (FEA1). This periplasmic protein is expressed under conditions of iron deficiency, but its mechanisms of function remain unknown. Because FEA1 has no amino-acid similarity to protein structures in the Protein Data Bank, its crystal structure cannot be solved by molecular replacement. Here, recombinant FEA1 protein lacking the N-terminal signal sequence was successfully purified and crystals of apo FEA1 were obtained by hanging-drop vapor diffusion. Neither selenomethionine substitution nor heavy-atom derivatization was successful; therefore, the phase problem of FEA1 crystals was solved by the native sulfur SAD method using long-wavelength X-rays (2.7 Å). Laser-cutting technology was used to increase the signal-to-noise ratio and derive an initial structure. This study will lead to further structural studies of FEA1 to understand its function and its links to the iron-assimilation pathway. |
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