4TQQ

Photosynthetic Reaction Center from R. sphaeroides Analyzed at Room Temperature on an X-ray Transparent Microfluidic Chip

Summary for 4TQQ

• Entry DOI: 10.2210/pdb4tqq/pdb
• Descriptor: Reaction center protein H chain, Reaction center protein L chain, Reaction center protein M chain, ... (9 entities in total)
• Functional Keywords: photosynthetic, membrane protein, photosynthesis
• Biological source: Rhodobacter sphaeroides; More
• Total number of polymer chains: 3
• Total formula weight: 97835.11

Authors

Schieferstein, J.M.,Khvostichenko, D.S.,Pawate, A.S.,Kenis, P.J.A. (deposition date: 2014-06-11, release date: 2014-07-16, Last modification date: 2023-09-27)

Primary citation

Khvostichenko, D.S.,Schieferstein, J.M.,Pawate, A.S.,Laible, P.D.,Kenis, P.J.
X-ray Transparent Microfluidic Chip for Mesophase-Based Crystallization of Membrane Proteins and On-Chip Structure Determination.
Cryst.Growth Des., 14:4886-4890, 2014

PubMed Abstract: Crystallization from lipidic mesophase matrices is a promising route to diffraction-quality crystals and structures of membrane proteins. The microfluidic approach reported here eliminates two bottlenecks of the standard mesophase-based crystallization protocols: (i) manual preparation of viscous mesophases and (ii) manual harvesting of often small and fragile protein crystals. In the approach reported here, protein-loaded mesophases are formulated in an X-ray transparent microfluidic chip using only 60 nL of the protein solution per crystallization trial. The X-ray transparency of the chip enables diffraction data collection from multiple crystals residing in microfluidic wells, eliminating the normally required manual harvesting and mounting of individual crystals. We validated our approach by on-chip crystallization of photosynthetic reaction center, a membrane protein from , followed by solving its structure to a resolution of 2.5 Å using X-ray diffraction data collected on-chip under ambient conditions. A moderate conformational change in hydrophilic chains of the protein was observed when comparing the on-chip, room temperature structure with known structures for which data were acquired under cryogenic conditions.

PubMed: 25285049
DOI: 10.1021/cg5011488

Experimental method

X-RAY DIFFRACTION (2.499 Å)