4CVT

Structure of Apobacterioferritin Y58F variant

Summary for 4CVT

• Entry DOI: 10.2210/pdb4cvt/pdb
• Related: 4CVP 4CVR 4CVS
• Descriptor: BACTERIOFERRITIN, ZINC ION (3 entities in total)
• Functional Keywords: oxidoreductase, electron transfer
• Biological source: ESCHERICHIA COLI
• Total number of polymer chains: 1
• Total formula weight: 18872.82

Authors

Hingorani, K.,Pace, R.,Whitney, S.,Murray, J.W.,Wydrzynski, T.,Cheah, M.H.,Smith, P.,Hillier, W. (deposition date: 2014-03-29, release date: 2014-08-20, Last modification date: 2023-12-20)

Primary citation

Hingorani, K.,Pace, R.,Whitney, S.,Murray, J.W.,Smith, P.,Cheah, M.H.,Wydrzynski, T.,Hillier, W.
Photo-Oxidation of Tyrosine in a Bio-Engineered Bacterioferritin 'Reaction Centre'-A Protein Model for Artificial Photosynthesis.
Biochim.Biophys.Acta, 1837:1821-, 2014

PubMed Abstract: The photosynthetic reaction centre (RC) is central to the conversion of solar energy into chemical energy and is a model for bio-mimetic engineering approaches to this end. We describe bio-engineering of a Photosystem II (PSII) RC inspired peptide model, building on our earlier studies. A non-photosynthetic haem containing bacterioferritin (BFR) from Escherichia coli that expresses as a homodimer was used as a protein scaffold, incorporating redox-active cofactors mimicking those of PSII. Desirable properties include: a di-nuclear metal binding site which provides ligands for bivalent metals, a hydrophobic pocket at the dimer interface which can bind a photosensitive porphyrin and presence of tyrosine residues proximal to the bound cofactors, which can be utilised as efficient electron-tunnelling intermediates. Light-induced electron transfer from proximal tyrosine residues to the photo-oxidised ZnCe6(•+), in the modified BFR reconstituted with both ZnCe6 and Mn(II), is presented. Three site-specific tyrosine variants (Y25F, Y58F and Y45F) were made to localise the redox-active tyrosine in the engineered system. The results indicate that: presence of bound Mn(II) is necessary to observe tyrosine oxidation in all BFR variants; Y45 the most important tyrosine as an immediate electron donor to the oxidised ZnCe6(•+) and that Y25 and Y58 are both redox-active in this system, but appear to function interchangebaly. High-resolution (2.1Å) crystal structures of the tyrosine variants show that there are no mutation-induced effects on the overall 3-D structure of the protein. Small effects are observed in the Y45F variant. Here, the BFR-RC represents a protein model for artificial photosynthesis.

PubMed: 25107631
DOI: 10.1016/J.BBABIO.2014.07.019

Experimental method

X-RAY DIFFRACTION (1.794 Å)