6X0Q

A Circular Permutant of the Tobacco Mosaic Virus (TMV) mutant Q101H coordinated with heme

Summary for 6X0Q

• Entry DOI: 10.2210/pdb6x0q/pdb
• Related: 3KML
• Descriptor: Capsid protein Circular Permutant, PROTOPORPHYRIN IX CONTAINING FE (2 entities in total)
• Functional Keywords: viral capsid proteins, designed heme binding protein, self-assembling proteins, viral protein
• Biological source: Tobacco mosaic virus (strain vulgare) (TMV); More
• Total number of polymer chains: 17
• Total formula weight: 306696.74

Authors

Dai, J.,Knott, G.J.,Francis, M.B. (deposition date: 2020-05-17, release date: 2020-12-09, Last modification date: 2023-10-18)

Primary citation

Dai, J.,Knott, G.J.,Fu, W.,Lin, T.W.,Furst, A.L.,Britt, R.D.,Francis, M.B.
Protein-Embedded Metalloporphyrin Arrays Templated by Circularly Permuted Tobacco Mosaic Virus Coat Proteins.
Acs Nano, 15:8110-8119, 2021

PubMed Abstract: Bioenergetic processes in nature have relied on networks of cofactors for harvesting, storing, and transforming the energy from sunlight into chemical bonds. Models mimicking the structural arrangement and functional crosstalk of the cofactor arrays are important tools to understand the basic science of natural systems and to provide guidance for non-natural functional biomaterials. Here, we report an artificial multiheme system based on a circular permutant of the tobacco mosaic virus coat protein (cpTMV). The double disk assembly of cpTMV presents a gap region sandwiched by the two -symmetrically related disks. Non-native bis-his coordination sites formed by the mutation of the residues in this gap region were computationally screened and experimentally tested. A cpTMV mutant Q101H was identified to create a circular assembly of 17 protein-embedded hemes. Biophysical characterization using X-ray crystallography, cyclic voltammetry, and electron paramagnetic resonance (EPR) suggested both structural and functional similarity to natural multiheme cytochrome proteins. This protein framework offers many further engineering opportunities for tuning the redox properties of the cofactors and incorporating non-native components bearing varied porphyrin structures and metal centers. Emulating the electron transfer pathways in nature using a tunable artificial system can contribute to the development of photocatalytic materials and bioelectronics.

PubMed: 33285072
DOI: 10.1021/acsnano.0c07165

Experimental method

X-RAY DIFFRACTION (3 Å)