Protein Machines at Work

This video shows a molecular view of the reactions that take place inside the pyruvate dehydrogenase complex, a protein machine found in the cell’s powerhouse, the mitochondria. 3D imaging of this machine by high-resolution electron microscopy reveals how the different components essential for the reaction are organized. Watch the flexible arms move inside the protein machine as pyruvate (an essential compound made from glucose) gets converted into acetyl-CoA (a precursor to the cell’s energy supply).

Credit: Jacqueline Milne and Sriram Subramaniam, Laboratory of Cell Biology, National Cancer Institute; Donald Bliss, National Library of Medicine; NIH


Molecular architecture and mechanism of an icosahedral pyruvate dehydrogenase complex: a multifunctional catalytic machine. Milne JL, Shi D, Rosenthal PB, Sunshine JS, Domingo GJ, Wu X, Brooks BR, Perham RN, Henderson R, Subramaniam S. EMBO J. 2002 Nov 1;21(21):5587-98.

Molecular structure of a 9-MDa icosahedral pyruvate dehydrogenase subcomplex containing the E2 and E3 enzymes using cryoelectron microscopy. Milne JL, Wu X, Borgnia MJ, Lengyel JS, Brooks BR, Shi D, Perham RN, Subramaniam S. J Biol Chem. 2006 Feb 17;281(7):4364-70.

Extended polypeptide linkers establish the spatial architecture of a pyruvate dehydrogenase multienzyme complex. Lengyel JS, Stott KM, Wu X, Brooks BR, Balbo A, Schuck P, Perham RN, Subramaniam S, Milne JL. Structure. 2008 Jan;16(1):93-103


7 thoughts on “Protein Machines at Work

  1. Lou,
    Not many people can understand this video. It’s a shame the amazing explanation is not hereon, and/or the application of this knowledge as in the director’s blog on Parkinson’s research.

  2. It’s amazing to watch, just absolutely amazing. That thing is actually working as a machine. And, that it can’t be seen under normal human circumstances, that’s utterly amazing. I don’t care what anyone may think, feel, or, comment negatively about it… but, there’s a God. Of which, may God bless us all… Everyone! Thank you, bye.

  3. This is amazing. It further confirmed that there is a supreme being behind our existence as science uncovers on a daily basis our complex machinery structures.

  4. Not sure I understand at all, but thanks to Jacqueline Milne and Sriram Subramaniam for their work against cancer.

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