This publication is based on work supported by award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). R.M.D. acknowledges support from the NSF Graduate Research Fellowship Program (GRFP). H.S. acknowledges funding by the NSF single investigator award (DMR-1104773). This work made use of the Cornell Center for Materials Research Shared Facilities, which are supported through the NSF MRSEC program (DMR-1120296) and the Cornell High Energy Synchrotron Source (CHESS), which is supported by the NSF 82 NIH/NIGMS via NSF award DMR-0936384, and MacCHESS supported by NIGMS award GM-103485. We thank Prof. E.M.V. Hoek and M. Pendergast for helpful discussions, and J. Weidman for SEM cross-sectional analysis of the ISV43 membrane.