Article
- The EMBO Journal (2007) 26, 3015 - 3024
- doi:10.1038/sj.emboj.7601731
Published online: 17 May 2007
Subject Category:
YscU recognizes translocators as export substrates of the Yersinia injectisome
Isabel Sorg1, Stefanie Wagner1, Marlise Amstutz1, Shirley A Müller1,2, Petr Broz1, Yvonne Lussi1, Andreas Engel1,2 and Guy R Cornelis1
- Biozentrum der Universität Basel, Basel, Switzerland
- ME Müller Institute for Structural Biology, Basel, Switzerland
Correspondence to:
Guy R Cornelis, Biozentrum, Universität Basel, Infection Biology, Klingelbergstrasse 50-70, Basel, CH 4056, Switzerland. Tel.: +41 61 267 21 10; Fax: +41 61 267 21 18; E-mail: guy.cornelis@unibas.ch
Received 28 March 2007; Accepted 27 April 2007
Abstract
YscU is an essential component of the export apparatus of the Yersinia injectisome. It consists of an N-terminal transmembrane domain and a long cytoplasmic C-terminal domain, which undergoes auto-cleavage at a NPTH site. Substitutions N263A and P264A prevented cleavage of YscU and abolished export of LcrV, YopB and YopD but not of Yop effectors. As a consequence, yscUN263A mutant bacteria made needles without the LcrV tip complex and they could not form translocation pores. The graft of the export signal of the effector YopE, at the N-terminus of LcrV, restored LcrV export and assembly of the tip complex. Thus, YscU cleavage is required to acquire the conformation allowing recognition of translocators, which represent an individual category of substrates in the hierarchy of export. In addition, yscUN263A mutant bacteria exported reduced amounts of the YscP ruler and made longer needles. Increasing YscP export resulted in needles with normal size, depending on the length of the ruler. Hence, the effect of the yscUN263A mutation on needle length was the consequence of a reduced YscP export.
Keywords:
- effectors,
- targeting,
- translocation,
- type III secretion,
- Yops
