TY - JOUR
T1 - FtsZ fiber bundling is triggered by a conformational change in bound GTP
AU - Marrington, Rachel
AU - Small, Elaine
AU - Rodger, Alison
AU - Dafforn, Timothy R.
AU - Addinall, Stephen G.
PY - 2004/11/19
Y1 - 2004/11/19
N2 - Polymer formation by the essential FtsZ protein plays a crucial role in the cytokinesis of most prokaryotes. Lateral associations between these FtsZ polymers to form bundles or sheets are widely predicted to be extremely important for FtsZ function in vivo. We have carried out a study in vitro of FtsZ polymer formation and bundling using linear dichroism (LD) to assess structural properties of the polymers. We demonstrate proof-of-principle experiments to show that LD can be used as a technique to follow FtsZ polymerization, and we present the LD spectra of FtsZ polymers. Our subsequent examination of FtsZ polymer bundling induced by calcium reveals a substantial increase in the LD signal indicative of increased polymer length and rigidity. We also detect a specific conformational change in the guanine moiety associated with bundling, whereas the conformation and configuration of the FtsZ monomers within the polymer remain largely unchanged. We demonstrate that other divalent cations can induce this conformational change in FtsZ-bound GTP coincident with polymer bundling. Therefore, we present "flipping" of the guanine moiety in FtsZ-bound GTP as a mechanism that explains the link between reduced GTPase activity, increased polymer stability, and polymer bundling.
AB - Polymer formation by the essential FtsZ protein plays a crucial role in the cytokinesis of most prokaryotes. Lateral associations between these FtsZ polymers to form bundles or sheets are widely predicted to be extremely important for FtsZ function in vivo. We have carried out a study in vitro of FtsZ polymer formation and bundling using linear dichroism (LD) to assess structural properties of the polymers. We demonstrate proof-of-principle experiments to show that LD can be used as a technique to follow FtsZ polymerization, and we present the LD spectra of FtsZ polymers. Our subsequent examination of FtsZ polymer bundling induced by calcium reveals a substantial increase in the LD signal indicative of increased polymer length and rigidity. We also detect a specific conformational change in the guanine moiety associated with bundling, whereas the conformation and configuration of the FtsZ monomers within the polymer remain largely unchanged. We demonstrate that other divalent cations can induce this conformational change in FtsZ-bound GTP coincident with polymer bundling. Therefore, we present "flipping" of the guanine moiety in FtsZ-bound GTP as a mechanism that explains the link between reduced GTPase activity, increased polymer stability, and polymer bundling.
UR - http://www.scopus.com/inward/record.url?scp=10344248919&partnerID=8YFLogxK
U2 - 10.1074/jbc.M404944200
DO - 10.1074/jbc.M404944200
M3 - Article
C2 - 15328358
AN - SCOPUS:10344248919
SN - 0021-9258
VL - 279
SP - 48821
EP - 48829
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 47
ER -