1TWB

SspB disulfide crosslinked to an ssrA degradation tag

1TWB の概要

• エントリーDOI: 10.2210/pdb1twb/pdb
• 分子名称: Stringent starvation protein B homolog, ssrA peptide (3 entities in total)
• 機能のキーワード: adaptor, protease, aaa+, specificity factor, hydrolase
• 由来する生物種: Haemophilus influenzae
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 26699.91

構造登録者

Bolon, D.N.,Grant, R.A.,Baker, T.A.,Sauer, R.T. (登録日: 2004-06-30, 公開日: 2004-11-16, 最終更新日: 2024-11-06)

主引用文献

Bolon, D.N.,Grant, R.A.,Baker, T.A.,Sauer, R.T.
Nucleotide-Dependent Substrate Handoff from the SspB Adaptor to the AAA+ ClpXP Protease.
Mol.Cell, 16:343-350, 2004

PubMed Abstract: The SspB adaptor enhances ClpXP degradation by binding the ssrA degradation tag of substrates and the AAA+ ClpX unfoldase. To probe the mechanism of substrate delivery, we engineered a disulfide bond between the ssrA tag and SspB and demonstrated otherwise normal interactions by solving the crystal structure. Although the covalent link prevents adaptor.substrate dissociation, ClpXP degraded GFP-ssrA that was disulfide bonded to the adaptor. Thus, crosslinked substrate must be handed directly from SspB to ClpX. The ssrA tag in the covalent adaptor complex interacted with ClpX.ATPgammaS but not ClpX.ADP, suggesting that handoff occurs in the ATP bound enzyme. By contrast, SspB alone bound ClpX in both nucleotide states. Similar handoff mechanisms will undoubtedly be used by many AAA+ adaptors and enzymes, allowing assembly of delivery complexes in either nucleotide state, engagement of the recognition tag in the ATP state, and application of an unfolding force to the attached protein following hydrolysis.

PubMed: 15525508
DOI: 10.1016/j.molcel.2004.10.001

実験手法

X-RAY DIFFRACTION (1.9 Å)