Nd J.W.T. contributed new reagents/analytic tools; W.D.S., M.C., P.C.C., A.L.C., L.C.D., B.M.H., L.E.K., A.K., S.L., S.D.M., H.M., L.P., P.R., S.S., W.M.S., Y.S., H.L.T., T. Tomo, T. Tsuchiya, Z.T.W., and R.E.B. analyzed data; and W.D.S. and M.C. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. Data deposition: The sequences reported in this p