Structure of CPV17 polyhedrin determined by the improved analysis of serial femtosecond crystallographic data.
Helen M GinnMarc MesserschmidtXiaoyun JiHanwen ZhangDanny AxfordRichard J GildeaGraeme WinterAaron S BrewsterJohan HattneArmin WagnerJonathan M GrimesGwyndaf EvansNicholas K SauterGeoff SuttonDavid I StuartPublished in: Nature communications (2015)
The X-ray free-electron laser (XFEL) allows the analysis of small weakly diffracting protein crystals, but has required very many crystals to obtain good data. Here we use an XFEL to determine the room temperature atomic structure for the smallest cytoplasmic polyhedrosis virus polyhedra yet characterized, which we failed to solve at a synchrotron. These protein microcrystals, roughly a micron across, accrue within infected cells. We use a new physical model for XFEL diffraction, which better estimates the experimental signal, delivering a high-resolution XFEL structure (1.75 Å), using fewer crystals than previously required for this resolution. The crystal lattice and protein core are conserved compared with a polyhedrin with less than 10% sequence identity. We explain how the conserved biological phenotype, the crystal lattice, is maintained in the face of extreme environmental challenge and massive evolutionary divergence. Our improved methods should open up more challenging biological samples to XFEL analysis.
Keyphrases
- room temperature
- high resolution
- amino acid
- ionic liquid
- protein protein
- transcription factor
- induced apoptosis
- binding protein
- minimally invasive
- mental health
- physical activity
- computed tomography
- cell cycle arrest
- mass spectrometry
- gene expression
- risk assessment
- machine learning
- dna methylation
- deep learning
- magnetic resonance
- cell proliferation
- tandem mass spectrometry