Table 1.

Effects of mutations in and around domain II loops of selected Cry toxins

GeneLoopSequenceMutationResidue(s)Effect on bindinga,bToxicity (fold)bInsectReference
CompetitionIrreversible
cry1Aa 1c FNYAAA313–315None−2×Lower B. mori 197
cry1Aa 2LYRRIILΔd 365–371−10×ND−1,000 B. mori 233
cry1Aa 2LYRRIILAAAAAAA365–371−10×ND−1,000 B. mori 233
cry1Ab e α8ALGS282–283NoneNoneNone M. sexta 211
cry1Ab α8ALGS282–283+10×ND+7 L. dispar 211
cry1Ab 2RRPAAA368–370No bindingND−667 M. sexta 309
cry1Ab 2RRPAAA368–370No bindingND−36 H. virescens 309
cry1Ab 2PFNIGIΔ370–375None−30%−600 M. sexta 307
cry1Ab 2PFNIGIΔ370–375None−30%−54.6 H. virescens 309
cry1Ab 2FA371−2×−35%−600 M. sexta 307
cry1Ab 2FA371+0.7×ND+1.6 H. virescens 309
cry1Ab 2FC371None−35%−600 M. sexta 309
cry1Ab 2FV371None−30%−400 M. sexta 309
cry1Ab 2FS371None−20%−40 M. sexta 309
cry1Ab 2FL371None−10%−10 M. sexta 309
cry1Ab 2FY371None−5%−6 M. sexta 309
cry1Ab 2FW371NoneNoneNone M. sexta 309
cry1Ab 2NA372−2×−20%−2 M. sexta 309
cry1Ab 2NA372−1.3×ND−1.6 H. virescens 309
cry1Ab 2NA372+4.4×None+8.5 L. dispar 308
cry1Ab 2NG372+4.4×None+8.5 L. dispar 308
cry1Ab 2GA374−2×−20×−348 M. sexta 307
cry1Ab 2GA374−5.7×ND−8.7 H. virescens 309
cry1Ab 2IA375None−5%−2.4 M. sexta 307
cry1Ab 2IA375−3.6×ND−4.9 H. virescens 309
cry1Ab 3SA438−1.5×None−4.7 M. sexta 310
cry1Ab 3GA439−11.7×None−103 M. sexta 310
cry1Ab 3FA440−8.9×None−19.6 M. sexta 310
cry1Ab 3SA441NoneNoneNone M. sexta 310
cry1Ab 3NA442−1.6×None−3.8 M. sexta 310
cry1Ab 3SA443−1.5×None−4.5 M. sexta 310
cry1Ac 1GYYVSF312–314−0.7×−7.7 M. sexta 349
cry1Ac 1GYYVYF312–314−1.8×−6.2 M. sexta 349
cry1Ac 1GYYVSY312–314+4.0×−1.2 M. sexta 349
cry1Ac 1GYYGYS312–314+2.6×−1.2 M. sexta 349
cry1Ac 1GYYGYF312–314+3.4×−1.1 M. sexta 349
cry1Ac 1GYYAYY312–314+2.2×−1.1 M. sexta 349
cry1Ac 1GYYASY312–314−2.2×−1.0 M. sexta 349
cry1Ac 1GYYGSY312–314−1.4×−1.0 M. sexta 349
cry1Ac 1GYYGFS312–314−1.2×−1.0 M. sexta 349
cry1Ac 1GYYGFF312–314NoneNone M. sexta 349
cry1Ac 2YRRPYRIP367–370−10.8×−7.4 M. sexta 349
cry1Ac 2YRRPYKKA367–370−7.7×−2.2 M. sexta 349
cry1Ac 2YRRPSKRP367–370−3.5×−2.4 M. sexta 349
cry1Ac 2YRRPFIRP367–370−1.2×−6.5 M. sexta 349
cry1Ac 2YRRPYTRP367–370−1.1×−5.8 M. sexta 349
cry1Ac 2YRRPYRRA367–370−1.1×−2.1 M. sexta 349
cry1Ac 2YRRPFKRA367–370NoneNone M. sexta 349
cry1Ac 2YRRPYRKP367–370None+1.8 M. sexta 349
cry1Ac 2YRRPFKRA367–370None−1.3 M. sexta 349
cry1Ac 2YRRPFKRA367–370None+2.0 M. sexta 349
cry1Ac 3SGFSSDFS438–441−14.8×>1,000 M. sexta 349
cry1Ac 3SGFSIVFS438–441−14.3×>1,000 M. sexta 349
cry1Ac 3SGFSSVFI439–441−8.2×>1,000 M. sexta 349
cry1Ac 3SGFSSVFS440–441−12.9×−33.3 M. sexta 349
cry1Ac 3SGFSSAFS438–441−12.3×−33.3 M. sexta 349
cry1Ac 3SGFSTASS439–441−4.8×−33.3 M. sexta 349
cry1Ac 3SGFSSAYS440–441−3.5×−33.3 M. sexta 349
cry1Ac 3SGFSSASS439–441−5.7×−11.1 M. sexta 349
Competition Irreversible
cry1Ac 3SGFS NGYI440–441 −2.8×None −11.1 M. sexta 349
cry1Ac 3SGFSIGFI438–441−3.4×None−6.3 M. sexta 349
cry1Ac 3SGFSTGYS439–441−1.9×None−2.6 M. sexta 349
cry1Ac 3SGFSSIGFS440–441NoneNone−2.6 M. sexta 349
cry1Ac 3SGFSSGSS438–441NoneNone−1.0 M. sexta 349
cry1Ac 3SGFSSGFT439–441+9.6×NoneNone M. sexta 349
cry1Ac 3SGFSSGYS440–441−1.5×NoneNone M. sexta 349
cry3A 1YYGNDAAAAA350–354−9×NDNone T. molitor 422
cry3A 2PSAA412–413NoneNDNone T. molitor 422
cry3A 3MQGSRGAAAAAA481–486−4×+20%+2.4 T. molitor 422
  • a Competition results are given as fold values, while irreversible binding results are given as fold values or percentages.

  • b Values with minus signs are decreases, while values with plus signs are increases.

  • c Sequences around, not in, loop 1.

  • d Δ, deletion of sequences.

  • e Cry1Ab and Cry1Ac loops predicted from alignment with Cry1Aa.