Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.|Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.|Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.|Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.|Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.|Center for Theoretical Biological Physics, Rice University, Houston, TX, United States of America.