@article {Gladkova189027, author = {Christina Gladkova and Alexander F. Schubert and Jane L. Wagstaff and Jonathan N. Pruneda and Stefan M.V. Freund and David Komander}, title = {An {\textquoteleft}invisible{\textquoteright} ubiquitin conformation is required for efficient phosphorylation by PINK1}, elocation-id = {189027}, year = {2017}, doi = {10.1101/189027}, publisher = {Cold Spring Harbor Laboratory}, abstract = {The Ser/Thr protein kinase PINK1 phosphorylates the well-folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We had previously shown that Ser65-phosphorylation results in a conformational change, in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation in which the last β-strand is retracted to extend the Ser65 loop and shorten the C-terminal tail. We here show using Chemical Exchange Saturation Transfer (CEST) NMR experiments, that a similar, C-terminally retracted (Ub-CR) conformation exists in wild-type Ub. Ub point mutations in the moving β5-strand and in neighbouring strands shift the Ub/Ub-CR equilibrium. This enabled functional studies of the two states, and we show that the Ub-CR conformation binds to the PINK1 kinase domain through its extended Ser65 loop and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub-CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded proteins or domains.}, URL = {https://www.biorxiv.org/content/early/2017/09/21/189027}, eprint = {https://www.biorxiv.org/content/early/2017/09/21/189027.full.pdf}, journal = {bioRxiv} }