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-Structure paper
タイトル | Structural basis of substrate recognition by a polypeptide processing and secretion transporter. |
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ジャーナル・号・ページ | Elife, Vol. 9, Year 2020 |
掲載日 | 2020年1月14日 |
著者 | Virapat Kieuvongngam / Paul Dominic B Olinares / Anthony Palillo / Michael L Oldham / Brian T Chait / Jue Chen / |
PubMed 要旨 | The peptidase-containing ATP-binding cassette transporters (PCATs) are unique members of the ABC transporter family that proteolytically process and export peptides and proteins. Each PCAT contains ...The peptidase-containing ATP-binding cassette transporters (PCATs) are unique members of the ABC transporter family that proteolytically process and export peptides and proteins. Each PCAT contains two peptidase domains that cleave off the secretion signal, two transmembrane domains forming a translocation pathway, and two nucleotide-binding domains that hydrolyze ATP. Previously the crystal structures of a PCAT from (PCAT1) were determined in the absence and presence of ATP, revealing how ATP binding regulates the protease activity and access to the translocation pathway. However, how the substrate CtA, a 90-residue polypeptide, is recognized by PCAT1 remained elusive. To address this question, we determined the structure of the PCAT1-CtA complex by electron cryo-microscopy (cryo-EM) to 3.4 Å resolution. The structure shows that two CtAs are bound via their N-terminal leader peptides, but only one is positioned for cleavage and translocation. Based on these results, we propose a model of how substrate cleavage, ATP hydrolysis, and substrate translocation are coordinated in a transport cycle. |
リンク | Elife / PubMed:31934861 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.35 Å |
構造データ | EMDB-21132, PDB-6v9z: |
由来 |
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キーワード | PROTEIN TRANSPORT / ATP-Binding Cassette |