Lon degrades stable substrates slowly but with enhanced processivity, redefining the attributes of a successful AAA+ protease.
Lon degrades stable substrates slowly but with enhanced processivity, redefining the attributes of a successful AAA+ protease.
复制标题
DOI：
10.1016/j.celrep.2023.113061
复制
发表时间：
2023-09-26
期刊：
影响因子：
8.8
通讯作者：
中科院分区：
文献类型：
--
作者：
Lon是一种广泛分布的AAA+（与多种细胞活性相关的ATP酶）蛋白酶，已知用于降解折叠不良和受损的蛋白质，并且通常被归类为弱蛋白质解折叠酶。在这里，使用Lon-degron对从Mesoplasma florum（MfLon和MfssrA，分别），我们进行合奏和单分子实验，以阐明MfLon功能的分子机制。值得注意的是，我们发现MfLon展开并降解稳定折叠的底物，并且这些展开的多肽的易位以约6个氨基酸的步长发生。此外，水解一个ATP所需的时间对应于步骤之间的停留时间，表明每个ATP水解燃料的“动力冲程”发生一个步骤。MfLon与相关AAA+酶的比较现在提供了强有力的证据，证明HCLR进化枝酶使用共享的动力冲程机制发挥功能，并且令人惊讶的是，MfLon比ClpXP和ClpAP更具进行性。我们建议，足够的解折叠酶强度和大量的持续合成能力的功能，有助于隆家族的进化成功。Kasal等人使用来自花中原体的细菌酶进行Lon蛋白酶的单分子表征，并发现HCLR进化枝AAA+解折叠酶的不同亚家族使用保守的ATP驱动的易位机制。此外，Lon是高度进行性的，并且是一种强大的解折叠酶，其似乎被调节以将底物降解至完成。
Lon is a widely distributed AAA+ (ATPases associated with diverse cellular activities) protease known for degrading poorly folded and damaged proteins and is often classified as a weak protein unfoldase. Here, using a Lon-degron pair from Mesoplasma florum (MfLon and MfssrA, respectively), we perform ensemble and single-molecule experiments to elucidate the molecular mechanisms underpinning MfLon function. Notably, we find that MfLon unfolds and degrades stably folded substrates and that translocation of these unfolded polypeptides occurs with a~ 6-amino-acid step size. Moreover, the time required to hydrolyze one ATP corresponds to the dwell time between steps, indicating that one step occurs per ATP-hydrolysis-fueled “power stroke.” Comparison of MfLon to related AAA+ enzymes now provides strong evidence that HCLR-clade enzymes function using a shared power-stroke mechanism and, surprisingly, that MfLon is more processive than ClpXP and ClpAP. We propose that ample unfoldase strength and substantial processivity are features that contribute to the Lon family’s evolutionary success. Kasal et al. perform single-molecule characterizations of Lon protease using the bacterial enzyme from Mesoplasma florum and discover that distinct subfamilies of the HCLR-clade AAA+ unfoldases use a conserved ATP-driven translocation mechanism. Furthermore, Lon is highly processive and a powerful unfoldase that appears tuned to degrade substrates to completion.
登录
查看更多内容
影响因子：
16.8
作者：
Martin, Andreas;Baker, Tania A.;Sauer, Robert T.
通讯作者：
Sauer, Robert T.
影响因子：
7.7
作者：
Fei X;Bell TA;Barkow SR;Baker TA;Sauer RT
通讯作者：
Sauer RT
影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
DOI：
10.1073/pnas.0910392106
发表时间：
2009-11-03
影响因子：
11.1
作者：
Gur, Eyal;Sauer, Robert T.
通讯作者：
Sauer, Robert T.
影响因子：
64.8
作者：
Kerssemakers, Jacob W. J.;Munteanu, E. Laura;Dogterom, Marileen
通讯作者：
Dogterom, Marileen