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-Structure paper
タイトル | Type 9 secretion system structures reveal a new protein transport mechanism. |
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ジャーナル・号・ページ | Nature, Vol. 564, Issue 7734, Page 77-82, Year 2018 |
掲載日 | 2018年11月7日 |
著者 | Frédéric Lauber / Justin C Deme / Susan M Lea / Ben C Berks / |
PubMed 要旨 | The type 9 secretion system (T9SS) is the protein export pathway of bacteria of the Gram-negative Fibrobacteres-Chlorobi-Bacteroidetes superphylum and is an essential determinant of pathogenicity in ...The type 9 secretion system (T9SS) is the protein export pathway of bacteria of the Gram-negative Fibrobacteres-Chlorobi-Bacteroidetes superphylum and is an essential determinant of pathogenicity in severe periodontal disease. The central element of the T9SS is a so-far uncharacterized protein-conducting translocon located in the bacterial outer membrane. Here, using cryo-electron microscopy, we provide structural evidence that the translocon is the T9SS protein SprA. SprA forms an extremely large (36-strand) single polypeptide transmembrane β-barrel. The barrel pore is capped on the extracellular end, but has a lateral opening to the external membrane surface. Structures of SprA bound to different components of the T9SS show that partner proteins control access to the lateral opening and to the periplasmic end of the pore. Our results identify a protein transporter with a distinctive architecture that uses an alternating access mechanism in which the two ends of the protein-conducting channel are open at different times. |
リンク | Nature / PubMed:30405243 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.5 - 3.7 Å |
構造データ | |
由来 |
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キーワード | PROTEIN TRANSPORT / Type 9 Secretion System Type IX Secretion System T9S folded protein secretion outer membrane protein |