[1] Baylor Coll Med, Program Struct & Computat Biol & Mol Biophys, Houston, TX 77030 USA
[2] Baylor Coll Med, Natl Ctr Macromol Imaging, Verna & Marrs Mclean Dept Biochem & Mol Biol, Houston, TX 77030 USA
[3] Univ Texas, Hlth Sci Ctr, Houston Med Sch, Dept Pathol & Lab Med, Houston, TX 77030 USA