Table 1. Alignment of the analogous imidacloprid binding residues in four imidacloprid metabolizing enzymes: CYP6ER1, CYP6CM1, CYP3A4, CYP6G1.

CYP6ER1	CYP6CM1	CYP3A4	CYP6G1	SRS location	Secondary structure
124Phe	130Phe	98Ser	124Phe	SRS-1	Loop between helices B and C
288Asp	224PHe	190Leu	218Phe	SRS-2	Loop between helices F and F’
289Pro	225Arg	191Arg	219Thr	SRS-2	Loop between helices F and F’
290Asp	226Phe	192Phe	220Phe	SRS-2	Loop between helices F and F’
246Phe	251Ala	219Val	245Phe	SRS-3	Loop between helices G’ and G
247Thr	252Val	220Phe	246Phe	SRS-3	Loop between helices G’ and G
312Leu	321Ser	283Phe	311Thr	SRS-4	Helix I (O2 binding motif)
313Ala	322Ala	284Ala	312Ala	SRS-4	Helix I (O2 binding motif)
314Gly	323Gly	285Gly	313Gly	SRS-4	Helix I (O2 binding motif)
317Thr	326Pro	288Thr	316Thr	SRS-4	Helix I (O2 binding motif)
374Gly	387Ala	348ILe	377Val	SRS-5	Loop between helix K and b-strand
375Pro	388Ser	349Ala	378Leu	SRS-5	Loop between helix K and b-strand
376Val	389Gly	350Met	379Pro	SRS-5	Loop between helix K and b-strand
487Thr	501Ser	460Gly	497Gly	SRS-6	C-terminal loop
488Phe	502Phe	461Gly	498Phe	SRS-6	C-terminal loop
489Val	503Thr	462Leu	499Val	SRS-6	C-terminal loop

Analyses were based on structure sequence alignment between the CYP6CM1 model and the CYP3A4 crystallographic structure together with sequence alignment to CYP6G1. Some of the residues that contribute to the stabilization of imidacloprid in the active site are also important in the stabilization of the heme and oxygen molecules.