RT Journal Article
SR Electronic
T1 Structure-based analysis of CysZ-mediated cellular uptake of sulfate
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 131318
DO 10.1101/131318
A1 Zahra Assur Sanghai
A1 Qun Liu
A1 Oliver B. Clarke
A1 Edgar Leal Pinto
A1 Brian Kloss
A1 Shantelle Tabuso
A1 James Love
A1 Marco Punta
A1 Surajit Banerjee
A1 Kanagalaghatta R. Rajashankar
A1 Burkhard Rost
A1 Diomedes Logothetis
A1 Matthias Quick
A1 Wayne A. Hendrickson
A1 Filippo Mancia
YR 2017
UL http://biorxiv.org/content/early/2017/04/27/131318.abstract
AB Sulfur, most abundantly found in the environment as sulfate (SO42-), is an essential element in metabolites required by all living cells, including amino acids, co-factors and vitamins. Current understanding of the cellular delivery of SO42- at the molecular level is limited however. CysZ has been described as a SO42- permease, but its sequence family is without known structural precedent. Based on crystallographic structure information, SO42- binding and uptake experiments in cells and proteoliposomes, and single-channel conductance measurements, we provide insight into the molecular mechanism of CysZ-mediated translocation of SO42- across membranes. CysZ properties differ markedly from those of known transporters and ion channels. The structures display a hitherto unknown fold with dual topology, assembling in CysZ from Pseudomonas denitrificans as a trimer of antiparallel dimers in the membrane. CysZ structures from two other species recapitulate dimers from this assembly. Mutational studies highlight the functional relevance of conserved CysZ residues.