Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP

Imaizumi, Y.; Takanuki, K.; Miyake, T.; Takemoto, M.; Hirata, K.; Hirose, M.; Oi, R.; Kobayashi, T.; Miyoshi, K.; Aruga, R.; Yokoyama, T.; Katagiri, S.; Matsuura, H.; Iwasaki, K.; Kato, T.; Kaneko, M. K.; Kato, Y.; Tajiri, M.; Akashi, S.; Nureki, O.; Hizukuri, Y.; Akiyama, Y.; Nogi, T.

doi:10.1101/2022.01.31.478169

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bioRxiv · 10.1101/2022.01.31.478169

Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP

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Abstract

Site-2 proteases are a conserved family of intramembrane proteases that cleave transmembrane substrates to regulate signal transduction and maintain proteostasis. Here, we elucidated crystal structures of inhibitor-bound forms of bacterial site-2 proteases including E. coli RseP. Our observations are consistent with a rearrangement of the RseP domains surrounding the active center to expose the substrate-binding site where a conserved electrostatic linkage between the transmembrane and membrane-associated domains mediates the conformational changes, suggesting that RseP has a gating mechanism to regulate substrate entry. Mutational analysis also supports that the substrate transmembrane helix is unwound by strand addition to the intramembrane {beta} sheet and is clamped at the active center for efficient cleavage. Furthermore, this substrate accommodation mechanism appears to be common across distinct intramembrane proteases.

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Imaizumi, Y., Takanuki, K., Miyake, T., Takemoto, M., Hirata, K., Hirose, M., Oi, R., Kobayashi, T., Miyoshi, K., Aruga, R., Yokoyama, T., Katagiri, S., Matsuura, H., Iwasaki, K., Kato, T., Kaneko, M. K., Kato, Y., Tajiri, M., Akashi, S., Nureki, O., Hizukuri, Y., Akiyama, Y., Nogi, T.. 2022-01-31. Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP. https://doi.org/10.1101/2022.01.31.478169

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