4J7O

Structure of the N-terminal Repeat Domain of Rickettsia Sca2

4J7O の概要

• エントリーDOI: 10.2210/pdb4j7o/pdb
• 分子名称: Putative surface cell antigen sca2, GLYCEROL (3 entities in total)
• 機能のキーワード: helical repeat, actin nucleation, actin, cell invasion
• 由来する生物種: Rickettsia conorii
• 細胞内の位置: Cell outer membrane (By similarity): Q92JF7
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 42484.53

構造登録者

Madasu, Y.,Dominguez, R. (登録日: 2013-02-13, 公開日: 2013-07-03, 最終更新日: 2024-02-28)

主引用文献

Madasu, Y.,Suarez, C.,Kast, D.J.,Kovar, D.R.,Dominguez, R.
Rickettsia Sca2 has evolved formin-like activity through a different molecular mechanism.
Proc.Natl.Acad.Sci.USA, 110:E2677-E2686, 2013

PubMed Abstract: Sca2 (surface cell antigen 2) is the only bacterial protein known to promote both actin filament nucleation and profilin-dependent elongation, mimicking eukaryotic formins to assemble actin comet tails for Rickettsia motility. We show that Sca2's functional mimicry of formins is achieved through a unique mechanism. Unlike formins, Sca2 is monomeric, but has N- and C-terminal repeat domains (NRD and CRD) that interact with each other for processive barbed-end elongation. The crystal structure of NRD reveals a previously undescribed fold, consisting of helix-loop-helix repeats arranged into an overall crescent shape. CRD is predicted to share this fold and might form together with NRD, a doughnut-shaped formin-like structure. In between NRD and CRD, proline-rich sequences mediate the incorporation of profilin-actin for elongation, and WASP-homology 2 (WH2) domains recruit actin monomers for nucleation. Sca2's α-helical fold is unusual among Gram-negative autotransporters, which overwhelmingly fold as β-solenoids. Rickettsia has therefore "rediscovered" formin-like actin nucleation and elongation.

PubMed: 23818602
DOI: 10.1073/pnas.1307235110

実験手法

X-RAY DIFFRACTION (2.175 Å)