This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Plasmodium, causative agents of malaria, exhibit cell traversal activity as a prelude to an obligatory developmental stage in hepatocytes and onset of malarial symptoms. Disruption of the Sporozoite Protein Essential for Cell Traversal-1 (SPECT1) gene in the early infection stage of Plasmodium (sporozoite) decreases cell traversal activity and reduces hepatocyte infection. Thus SPECT1 is a potential target for vaccine development. Here we propose to assist with malarial vaccine development and determining the molecular mechanism of SPECT1 function by solving its x-ray crystal structure.