Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Centrins are calmodulin-like proteins present in centrosomes and yeast spindle pole bodies (SPBs) and have essential functions in their duplication. The Saccharomyces cerevisiae centrin, Cdc31p, binds Sfi1p on multiple conserved repeats; both proteins localize to the SPB half-bridge, where the new SPB is assembled. The crystal structures of Sfi1p-centrin complexes containing several repeats show Sfi1p as an alpha helix with centrins wrapped around each repeat and similar centrin-centrin contacts between each repeat. Electron microscopy (EM) shadowing of an Sfi1p-centrin complex with 15 Sfi1 repeats and 15 centrins bound showed filaments 60 nm long, compatible with all the Sfi1 repeats as a continuous alpha helix. Immuno-EM localization of the Sfi1p N and C termini showed Sfi1p-centrin filaments spanning the length of the half-bridge with the Sfi1p N terminus at the SPB. This suggests a model for SPB duplication where the half-bridge doubles in length by association of the Sfi1p C termini, thereby providing a new Sfi1p N terminus to initiate SPB assembly.

Original publication

DOI

10.1083/jcb.200603153

Type

Journal article

Journal

J Cell Biol

Publication Date

19/06/2006

Volume

173

Pages

867 - 877

Keywords

Binding Sites, Calcium-Binding Proteins, Cell Cycle Proteins, Crystallography, X-Ray, Mass Spectrometry, Microtubule Proteins, Models, Molecular, Protein Binding, Protein Structure, Tertiary, Repetitive Sequences, Amino Acid, Repressor Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Sequence Analysis, Protein, Spindle Apparatus