Mikhail Kudryashev / Ray Yu-Ruei Wang / Maximilian Brackmann / Sebastian Scherer / Timm Maier / David Baker / Frank DiMaio / Henning Stahlberg / Edward H Egelman / Marek Basler /
PubMed 要旨
Bacteria use rapid contraction of a long sheath of the type VI secretion system (T6SS) to deliver effectors into a target cell. Here, we present an atomic-resolution structure of a native contracted ...Bacteria use rapid contraction of a long sheath of the type VI secretion system (T6SS) to deliver effectors into a target cell. Here, we present an atomic-resolution structure of a native contracted Vibrio cholerae sheath determined by cryo-electron microscopy. The sheath subunits, composed of tightly interacting proteins VipA and VipB, assemble into a six-start helix. The helix is stabilized by a core domain assembled from four β strands donated by one VipA and two VipB molecules. The fold of inner and middle layers is conserved between T6SS and phage sheaths. However, the structure of the outer layer is distinct and suggests a mechanism of interaction of the bacterial sheath with an accessory ATPase, ClpV, that facilitates multiple rounds of effector delivery. Our results provide a mechanistic insight into assembly of contractile nanomachines that bacteria and phages use to translocate macromolecules across membranes.
EMDB-2699: VipA/VipB, contractile sheath of the type VI secretion system PDB-3j9g: Atomic model of the VipA/VipB, the type six secretion system contractile sheath of Vibrio cholerae from cryo-EM 手法: EM (らせん対称) / 解像度: 3.5 Å
由来
vibrio cholerae o1 biovar el tor str. n16961 (コレラ菌)