12 research outputs found
Transmembrane Complexes of DAP12 Crystallized in Lipid Membranes Provide Insights into Control of Oligomerization in Immunoreceptor Assembly
The membrane-spanning α helices of single-pass receptors play crucial roles in stabilizing oligomeric structures and transducing biochemical signals across the membrane. Probing intermolecular transmembrane interactions in single-pass receptors presents unique challenges, reflected in a gross underrepresentation of their membrane-embedded domains in structural databases. Here, we present two high-resolution structures of transmembrane assemblies from a eukaryotic single-pass protein crystallized in a lipidic membrane environment. Trimeric and tetrameric structures of the immunoreceptor signaling module DAP12, determined to 1.77-Å and 2.14-Å resolution, respectively, are organized by the same polar surfaces that govern intramembrane assembly with client receptors. We demonstrate that, in addition to the well-studied dimeric form, these trimeric and tetrameric structures are made in cells, and their formation is competitive with receptor association in the ER. The polar transmembrane sequences therefore act as primary determinants of oligomerization specificity through interplay between charge shielding and sequestration of polar surfaces within helix interfaces
Prevention of stem growth inhibition and alleviation of intumescence formation in potato plantletsin vitro by yellow filters
High-Throughput Production and Structural Characterization of Libraries of Self-Assembly Lipidic Cubic Phase Materials
A protocol is presented for the high-throughput (HT)
production
of lyotropic liquid crystalline phases from libraries of lipids and
lipid mixtures using standard liquid dispensing robotics, implementing
methods that circumvent the problems traditionally associated with
handling the highly viscous cubic phase. In addition, the ability
to structurally characterize lipidic phases and assess functionality
for membrane proteins contained within cubic phases, in a HT manner,
is demonstrated. The techniques are combined and exemplified using
the application of membrane protein crystallization within lipidic
cubic phases