3D PSII supercomplex; here
Jon Nield - Scientist - a brief autobiography

During a highly rewarding summer vacation position in 1992, aged 19 Jon decided that a career in science would be an excellent pursuit. In the autumn of 1993, at the beginning of his Ph.D. studies, Jon isolated a novel, membrane-bound protein 'supercomplex' of photosystem II (PSII) from higher plants. Throughout his Ph.D. studies ('93-'97) he fully characterised this supercomplex biochemically with 14 different techniques and found that this macromolecular assembly retained bound components of the light harvesting complex (Lhcb1, 2, 4 and 5) in addition to the soluble oxygen-evolution enhancing extrinsic polypeptides (PsbO, PsbQ and PsbP). This work was first revealed structurally in a co-authored paper (PNAS 1995), and further investigations probed such complexes from cyanobacteria and green algae. For his first post-doctoral position ('97-99), he wished to visualise these protein assemblies in 3D and chose to use cryo- and negative stain electron microscopy (EM) with single particle image processing techniques. For his second post-doc. he tackled issues of sample heterogeneity through the application of computer CPU-intensive classification procedures. To date this has yielded many 3D structures at resolutions of up to 1.7 nm for higher plants and 2.5 nm for green algae and cyanobacteria. Jon has co-authored a review outlining these techniques: Prog. Mol. Biol. Biophys. (2001) 75, 121-164.
     Jon held a Royal Society University Research Fellowship position at Imperial College, with the goals to visulaise medium resolution macro-molecular protein frameworks, primarily for the investigation of photosynthetic structure / function relationships (2001-2012). This was transferred to The School of Biological and Chemical Sciences (in 2007) where he continues in a tenured position. He has published almost 50 refereed articles, including subjects as above plus X-ray crystallography (J. Struct. Biol. 2003) and protein folding prediction using internet-based databases and alignment tools (J. Biol. Chem. 2002).
     In one of these investigations, a discovery was made with Thomas Bibby and James Barber at Imperial College, where an 18-subunit ring of a photosystem II PsbC-like protein was observed to surround the trimeric core of Photosystem I, in an iron-stressed cyanobacterium Synechocystis PCC6803 (Nature Aug. 2001). This was followed by a second observation of such a ring, this time of 'Pcb' proteins surrounding a PSI trimer in the green oxyphotobacterium Prochlorococcus (Nature Oct. 2001). Furthermore, these PsbC-like proteins were shown to be expressed around both PSI and PSII, in Prochlorococcus (Nature 2003) and Prochloron (PNAS 2003), in collaboration locally & with French/Australian groups, respectively. 3D structures for a LHCI-PSI supercomplex from the green alga, Chlamydomonas reinhardtii, (J. Biol. Chem. 2003; cited in Stryer / Lehninger textbooks; 2007) including supercomplexes fixed in different functional states (FEBS J 2005), phage shock protein (PspA; J. Biol. Chem. 2004), refinement of the LHCII-PSII plant supercomplex model (BBA Bioenergetics 2006), investigating protease activity (J. Biol. Chem., 2006), insectotoxin (Toxicon, 2007) and atomic force microscopy on photosynthetic membranes (Biochemistry, 2008) are other highlights. The highly challenging arena of PSI assembly intermediates has been probed in (2009) in collaboration with Japanese, German and Swiss groups; in 2012 the first three-dimensional map for the holoenzyme of the PSII protease FtsH was revealed at a resolution of 26 Angstroem (The Plant Cell 2009 & 2012).
     Jon has taught UG classes (Molecular Photobioenergetics/Calvin CycleLectures; 120 students), M.Sc. and Undergraduate projects, as well as providing image processing/ TEM guidance for 6 Ph.D projects. He has set and marked UG exam questions, and been an examiner for UG final year projects. Two BSc students were hosted per year via Imperial College's Undergraduate Research Opportunities Program (UROP; www.urop.ic.ac.uk). Jon constantly referees publications with several journals for the scientific community and was an Associate Editor of Photochemical & Photobiological Sciences from 2005-2009 (www.rsc.org/pps). He has been, concurrently, Staff Representative on Faculty and GM-safety committees, and Divisional seminar series organiser and host (e.g. 26 lectures in 18 months). He has sat on Departmental IT provision, Employability and Imaging Centre committees.
     All original scientific content within this website is copyright of the relevant authors, institutions and/or the journals that it is published in. <updated 14th August 2014>

© Jon Nield, 2000-2014