Open AccessCrystallization and preliminary X‐ray analysis of the FliH–FliI complex responsible for bacterial flagellar type III protein export
Author(s) -
Uchida Yumiko,
Minamino Tohru,
Namba Keiichi,
Imada Katsumi
Publication year - 2012
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309112030801
Subject(s) - flagellum , cytoplasm , orthorhombic crystal system , crystallization , crystallography , chemistry , membrane , atpase , biophysics , microbiology and biotechnology , biology , biochemistry , crystal structure , enzyme , organic chemistry , gene
The bacterial flagellar proteins are translocated into the central channel of the flagellum by a specific protein‐export apparatus for self‐assembly at the distal growing end. FliH and FliI are soluble components of the export apparatus and form an FliH 2 –FliI heterotrimer in the cytoplasm. FliI is an ATPase and the FliH 2 –FliI complex delivers export substrates from the cytoplasm to an export gate made up of six integral membrane proteins of the export apparatus. In this study, an FliH C fragment consisting of residues 99–235 was co‐purified with FliI and the FliH C2 –FliI complex was crystallized. Crystals were obtained using the hanging‐drop vapour‐diffusion technique with PEG 400 as a precipitant. The crystals belonged to the orthorhombic space group P 2 1 2 1 2 1 , with unit‐cell parameters a = 133.7, b = 147.3, c = 164.2 Å, and diffracted to 3.0 Å resolution.